http://www.math.wisc.edu/wiki/api.php?action=feedcontributions&user=Rdavis&feedformat=atomUW-Math Wiki - User contributions [en]2019-08-20T14:00:34ZUser contributionsMediaWiki 1.30.1http://www.math.wisc.edu/wiki/index.php?title=NTS&diff=17388NTS2019-04-25T00:49:13Z<p>Rdavis: </p>
<hr />
<div>= Number Theory / Representation Theory Seminar, University of Wisconsin - Madison =<br />
<br />
<br />
*'''When:''' Thursdays, 2:30 PM – 3:30 PM<br />
*'''Where:''' Van Vleck B113<br />
*Please join the [https://mailhost.math.wisc.edu/mailman/listinfo/nts NT/RT mailing list:] (you must be on a math department computer to use this link).<br />
<br />
There is also an accompanying [https://www.math.wisc.edu/wiki/index.php/NTSGrad_Spring_2019 graduate-level seminar], which meets on Tuesdays.<br><br />
<br />
You can find our Fall 2018 speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Fall_2018_Semester Fall 2018].<br />
<br><br />
You can find our previous speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Spring_2018_Semester Spring 2018].<br />
<br />
= Spring 2019 Semester =<br />
<br />
<center><br />
<br />
{| style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" width="300" align="center"|'''Date'''<br />
| bgcolor="#F0A0A0" width="300" align="center"|'''Speaker''' (click for homepage)<br />
| bgcolor="#BCD2EE" width="300" align="center"|'''Title''' (click for abstract)<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 23<br />
'''Wed. Room VV B231'''<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.princeton.edu/~yunqingt/ Yunqing Tang (Princeton University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_23 Reductions of abelian surfaces over global function fields]<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 24<br />
| bgcolor="#F0B0B0" align="center" | Hassan-Mao-Smith--Zhu<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_24 The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Jan 31<br />
| bgcolor="#F0B0B0" align="center" | [https://faculty.math.illinois.edu/~kpratt4/ Kyle Pratt (University of Illinois at Urbana-Champaign)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_31 Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 7 <br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~shamgar/ Shamgar Gurevich (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_7 Harmonic Analysis on $GL_n$ over finite fields] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 14<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~thyang/ Tonghai Yang (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_14 The Lambda invariant and its CM values]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 21<br />
| bgcolor="#F0B0B0" align="center" | No Seminar<br />
| bgcolor="#BCE2FE"|<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 28<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.columbia.edu/~brianrl/ Brian Lawrence (the University of Chicago)] <br />
| bgcolor="#BCE2FE"|[https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_28 Diophantine problems and a p-adic period map.] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 7<br />
| bgcolor="#F0B0B0" align="center" |[https://sites.google.com/view/masoudzargar/ Masoud Zargar (Regensburg)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_7 Sections of quadrics over the affine line] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 14<br />
| bgcolor="#F0B0B0" align="center" | [http://www.its.caltech.edu/~mantovan/ Elena Mantovan (Caltech)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_14 p-adic automorphic forms, differential operators and Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 21<br />
| bgcolor="#F0B0B0" align="center" | Spring Break<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 28<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.ucsb.edu/~agboola/ Adebisi Agboola (UCSB)] <br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_28 Relative K-groups and rings of integers]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 4<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.tamu.edu/~wltsai/ Wei-Lun Tsai (Texas A&M University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_4 Hecke L-functions and $\ell$ torsion in class groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 11<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~tmcadam/ Taylor McAdam (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Almost-prime times in horospherical flows]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 18 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~ila/ Ila Varma (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_18 Malle's Conjecture for octic $D_4$-fields.]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''10:00-11:00 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://bushm.academic.wlu.edu Michael Bush (Washington & Lee)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Interactions between group theory and number theory]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''11:15-12:15 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://people.carleton.edu/~rfjones/ Rafe Jones (Carleton College)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25_2 Eventually stable polynomials and arboreal Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | [https://math.rice.edu/~jb93/ Jen Berg (Rice University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25_NTS Rational points on conic bundles over elliptic curves with positive rank] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''4:00-5:00 Room VV B239'''<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.unl.edu/~jwalker7/ Judy Walker (Nebraska)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25_3 Derangements of Finite Groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 2<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~mmwood/ Melanie Wood (UW-Madison)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 9 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.mathcs.emory.edu/~dzb/ David Zureick-Brown (Emory College of Arts and Sciences)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
|}<br />
</center><br />
<br />
<br><br />
<br />
*to be confirmed<br />
<br />
= Organizer contact information =<br />
<br />
[http://www.math.wisc.edu/~ntalebiz/ Naser Talebizadeh Sardari]<br />
<br />
[http://www.math.wisc.edu/~shusterman/ Mark Shusterman]<br />
<br />
[http://www.math.wisc.edu/~ruixiang/ Ruixiang Zhang]<br />
----<br />
Return to the [[Algebra|Algebra Group Page]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS&diff=17387NTS2019-04-25T00:47:43Z<p>Rdavis: </p>
<hr />
<div>= Number Theory / Representation Theory Seminar, University of Wisconsin - Madison =<br />
<br />
<br />
*'''When:''' Thursdays, 2:30 PM – 3:30 PM<br />
*'''Where:''' Van Vleck B113<br />
*Please join the [https://mailhost.math.wisc.edu/mailman/listinfo/nts NT/RT mailing list:] (you must be on a math department computer to use this link).<br />
<br />
There is also an accompanying [https://www.math.wisc.edu/wiki/index.php/NTSGrad_Spring_2019 graduate-level seminar], which meets on Tuesdays.<br><br />
<br />
You can find our Fall 2018 speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Fall_2018_Semester Fall 2018].<br />
<br><br />
You can find our previous speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Spring_2018_Semester Spring 2018].<br />
<br />
= Spring 2019 Semester =<br />
<br />
<center><br />
<br />
{| style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" width="300" align="center"|'''Date'''<br />
| bgcolor="#F0A0A0" width="300" align="center"|'''Speaker''' (click for homepage)<br />
| bgcolor="#BCD2EE" width="300" align="center"|'''Title''' (click for abstract)<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 23<br />
'''Wed. Room VV B231'''<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.princeton.edu/~yunqingt/ Yunqing Tang (Princeton University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_23 Reductions of abelian surfaces over global function fields]<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 24<br />
| bgcolor="#F0B0B0" align="center" | Hassan-Mao-Smith--Zhu<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_24 The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Jan 31<br />
| bgcolor="#F0B0B0" align="center" | [https://faculty.math.illinois.edu/~kpratt4/ Kyle Pratt (University of Illinois at Urbana-Champaign)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_31 Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 7 <br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~shamgar/ Shamgar Gurevich (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_7 Harmonic Analysis on $GL_n$ over finite fields] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 14<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~thyang/ Tonghai Yang (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_14 The Lambda invariant and its CM values]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 21<br />
| bgcolor="#F0B0B0" align="center" | No Seminar<br />
| bgcolor="#BCE2FE"|<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 28<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.columbia.edu/~brianrl/ Brian Lawrence (the University of Chicago)] <br />
| bgcolor="#BCE2FE"|[https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_28 Diophantine problems and a p-adic period map.] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 7<br />
| bgcolor="#F0B0B0" align="center" |[https://sites.google.com/view/masoudzargar/ Masoud Zargar (Regensburg)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_7 Sections of quadrics over the affine line] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 14<br />
| bgcolor="#F0B0B0" align="center" | [http://www.its.caltech.edu/~mantovan/ Elena Mantovan (Caltech)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_14 p-adic automorphic forms, differential operators and Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 21<br />
| bgcolor="#F0B0B0" align="center" | Spring Break<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 28<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.ucsb.edu/~agboola/ Adebisi Agboola (UCSB)] <br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_28 Relative K-groups and rings of integers]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 4<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.tamu.edu/~wltsai/ Wei-Lun Tsai (Texas A&M University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_4 Hecke L-functions and $\ell$ torsion in class groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 11<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~tmcadam/ Taylor McAdam (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Almost-prime times in horospherical flows]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 18 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~ila/ Ila Varma (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_18 Malle's Conjecture for octic $D_4$-fields.]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''10:00-11:00 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://bushm.academic.wlu.edu Michael Bush (Washington & Lee)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Interactions between group theory and number theory]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''11:15-12:15 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://people.carleton.edu/~rfjones/ Rafe Jones (Carleton College)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25_2 Eventually stable polynomials and arboreal Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | [https://math.rice.edu/~jb93/ Jen Berg (Rice University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25_3 Rational points on conic bundles over elliptic curves with positive rank] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''4:00-5:00 Room VV B239'''<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.unl.edu/~jwalker7/ Judy Walker (Nebraska)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25_4 Derangements of Finite Groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 2<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~mmwood/ Melanie Wood (UW-Madison)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 9 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.mathcs.emory.edu/~dzb/ David Zureick-Brown (Emory College of Arts and Sciences)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
|}<br />
</center><br />
<br />
<br><br />
<br />
*to be confirmed<br />
<br />
= Organizer contact information =<br />
<br />
[http://www.math.wisc.edu/~ntalebiz/ Naser Talebizadeh Sardari]<br />
<br />
[http://www.math.wisc.edu/~shusterman/ Mark Shusterman]<br />
<br />
[http://www.math.wisc.edu/~ruixiang/ Ruixiang Zhang]<br />
----<br />
Return to the [[Algebra|Algebra Group Page]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS&diff=17386NTS2019-04-25T00:44:14Z<p>Rdavis: </p>
<hr />
<div>= Number Theory / Representation Theory Seminar, University of Wisconsin - Madison =<br />
<br />
<br />
*'''When:''' Thursdays, 2:30 PM – 3:30 PM<br />
*'''Where:''' Van Vleck B113<br />
*Please join the [https://mailhost.math.wisc.edu/mailman/listinfo/nts NT/RT mailing list:] (you must be on a math department computer to use this link).<br />
<br />
There is also an accompanying [https://www.math.wisc.edu/wiki/index.php/NTSGrad_Spring_2019 graduate-level seminar], which meets on Tuesdays.<br><br />
<br />
You can find our Fall 2018 speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Fall_2018_Semester Fall 2018].<br />
<br><br />
You can find our previous speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Spring_2018_Semester Spring 2018].<br />
<br />
= Spring 2019 Semester =<br />
<br />
<center><br />
<br />
{| style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" width="300" align="center"|'''Date'''<br />
| bgcolor="#F0A0A0" width="300" align="center"|'''Speaker''' (click for homepage)<br />
| bgcolor="#BCD2EE" width="300" align="center"|'''Title''' (click for abstract)<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 23<br />
'''Wed. Room VV B231'''<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.princeton.edu/~yunqingt/ Yunqing Tang (Princeton University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_23 Reductions of abelian surfaces over global function fields]<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 24<br />
| bgcolor="#F0B0B0" align="center" | Hassan-Mao-Smith--Zhu<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_24 The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Jan 31<br />
| bgcolor="#F0B0B0" align="center" | [https://faculty.math.illinois.edu/~kpratt4/ Kyle Pratt (University of Illinois at Urbana-Champaign)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_31 Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 7 <br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~shamgar/ Shamgar Gurevich (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_7 Harmonic Analysis on $GL_n$ over finite fields] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 14<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~thyang/ Tonghai Yang (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_14 The Lambda invariant and its CM values]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 21<br />
| bgcolor="#F0B0B0" align="center" | No Seminar<br />
| bgcolor="#BCE2FE"|<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 28<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.columbia.edu/~brianrl/ Brian Lawrence (the University of Chicago)] <br />
| bgcolor="#BCE2FE"|[https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_28 Diophantine problems and a p-adic period map.] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 7<br />
| bgcolor="#F0B0B0" align="center" |[https://sites.google.com/view/masoudzargar/ Masoud Zargar (Regensburg)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_7 Sections of quadrics over the affine line] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 14<br />
| bgcolor="#F0B0B0" align="center" | [http://www.its.caltech.edu/~mantovan/ Elena Mantovan (Caltech)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_14 p-adic automorphic forms, differential operators and Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 21<br />
| bgcolor="#F0B0B0" align="center" | Spring Break<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 28<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.ucsb.edu/~agboola/ Adebisi Agboola (UCSB)] <br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_28 Relative K-groups and rings of integers]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 4<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.tamu.edu/~wltsai/ Wei-Lun Tsai (Texas A&M University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_4 Hecke L-functions and $\ell$ torsion in class groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 11<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~tmcadam/ Taylor McAdam (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Almost-prime times in horospherical flows]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 18 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~ila/ Ila Varma (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_18 Malle's Conjecture for octic $D_4$-fields.]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''10:00-11:00 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://bushm.academic.wlu.edu Michael Bush (Washington & Lee)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Interactions between group theory and number theory]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''11:15-12:15 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://people.carleton.edu/~rfjones/ Rafe Jones (Carleton College)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Eventually stable polynomials and arboreal Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | [https://math.rice.edu/~jb93/ Jen Berg (Rice University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25_NTS Rational points on conic bundles over elliptic curves with positive rank] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''4:00-5:00 Room VV B239'''<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.unl.edu/~jwalker7/ Judy Walker (Nebraska)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Derangements of Finite Groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 2<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~mmwood/ Melanie Wood (UW-Madison)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 9 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.mathcs.emory.edu/~dzb/ David Zureick-Brown (Emory College of Arts and Sciences)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
|}<br />
</center><br />
<br />
<br><br />
<br />
*to be confirmed<br />
<br />
= Organizer contact information =<br />
<br />
[http://www.math.wisc.edu/~ntalebiz/ Naser Talebizadeh Sardari]<br />
<br />
[http://www.math.wisc.edu/~shusterman/ Mark Shusterman]<br />
<br />
[http://www.math.wisc.edu/~ruixiang/ Ruixiang Zhang]<br />
----<br />
Return to the [[Algebra|Algebra Group Page]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS_ABSTRACTSpring2019&diff=17385NTS ABSTRACTSpring20192019-04-25T00:41:26Z<p>Rdavis: </p>
<hr />
<div>Return to [https://www.math.wisc.edu/wiki/index.php/NTS ]<br />
<br />
<br />
== Jan 23 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Yunqing Tang '''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Reductions of abelian surfaces over global function fields<br />
|-<br />
| bgcolor="#BCD2EE" | For a non-isotrivial ordinary abelian surface $A$ over a global function field, under mild assumptions, we prove that there are infinitely many places modulo which $A$ is geometrically isogenous to the product of two elliptic curves. This result can be viewed as a generalization of a theorem of Chai and Oort. This is joint work with Davesh Maulik and Ananth Shankar.<br />
<br />
|} <br />
</center><br />
<br />
<br><br />
<br />
== Jan 24 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Hassan-Mao-Smith--Zhu'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Assume a polynomial-time algorithm for factoring integers, Conjecture~\ref{conj}, $d\geq 3,$ and $q$ and $p$ prime numbers, where $p\leq q^A$ for some $A>0$. We develop a polynomial-time algorithm in $\log(q)$ that lifts every $\mathbb{Z}/q\mathbb{Z}$ point of $S^{d-2}\subset S^{d}$ to a $\mathbb{Z}[1/p]$ point of $S^d$ with the minimum height. We implement our algorithm for $d=3 \text{ and }4$. Based on our numerical results, we formulate a conjecture which can be checked in polynomial-time and gives the optimal bound on the diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$. <br />
<br />
|} <br />
</center><br />
<br />
<br />
== Jan 31 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Kyle Pratt'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: I will discuss recent work, joint with Bui, Robles, and Zaharescu, on a moment problem for Dirichlet $L$-functions. By way of motivation I will spend some time discussing the Lindel\"of Hypothesis, and work of Bettin, Chandee, and Radziwi\l\l. The talk will be accessible, as I will give lots of background information and will not dwell on technicalities. <br />
<br />
|} <br />
</center><br />
<br />
== Feb 7 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Shamgar Gurevich'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Harmonic Analysis on $GL_n$ over finite fields<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: There are many formulas that express interesting properties of a group G in terms of sums over its characters.<br />
For evaluating or estimating these sums, one of the most salient quantities to understand is the {\it character ratio}:<br />
$$trace (\rho(g))/dim (\rho),$$<br />
for an irreducible representation $\rho$ of G and an element g of G. For example, Diaconis and Shahshahani stated a formula of this type for analyzing G-biinvariant random walks on G. It turns out that, for classical groups G over finite fields (which provide most examples of finite simple groups), there is a natural invariant of representations that provides strong information on the character ratio. We call this invariant {\it rank}. This talk will discuss the notion of rank for GLn over finite fields, and apply the results to random walks. This is joint work with Roger Howe (TAMU).<br />
<br />
|} <br />
</center><br />
<br />
== Feb 14 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Tonghai Yang'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | The Lambda invariant and its CM values<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: The Lambda invariant which parametrizes elliptic curves with two torsions (X_0(2)) has some interesting properties, some similar to that of the j-invariants, and some not. For example, $\lambda(\frac{d+\sqrt d}2)$ is a unit sometime. In this talk, I will briefly describe some of the properties. This is joint work with Hongbo Yin and Peng Yu.<br />
<br />
|} <br />
</center><br />
<br />
== Feb 28 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Brian Lawrence'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Diophantine problems and a p-adic period map.<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: I will outline a proof of Mordell's conjecture / Faltings's theorem using p-adic Hodge theory. Joint with Akshay Venkatesh.<br />
<br />
|} <br />
</center><br />
<br />
== March 7==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Masoud Zargar'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Sections of quadrics over the affine line<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Abstract: Suppose we have a quadratic form Q(x) in d\geq 4 variables over F_q[t] and f(t) is a polynomial over F_q. We consider the affine variety X given by the equation Q(x)=f(t) as a family of varieties over the affine line A^1_{F_q}. Given finitely many closed points in distinct fibers of this family, we ask when there exists a section passing through these points. We study this problem using the circle method over F_q((1/t)). Time permitting, I will mention connections to Lubotzky-Phillips-Sarnak (LPS) Ramanujan graphs. Joint with Naser T. Sardari<br />
<br />
|} <br />
</center><br />
<br />
== March 14==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Elena Mantovan'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | p-adic automorphic forms, differential operators and Galois representations<br />
|-<br />
| bgcolor="#BCD2EE" | A strategy pioneered by Serre and Katz in the 1970s yields a construction of p-adic families of modular forms via the study of Serre's weight-raising differential operator Theta. This construction is a key ingredient in Deligne-Serre's theorem associating Galois representations to modular forms of weight 1, and in the study of the weight part of Serre's conjecture. In this talk I will discuss recent progress towards generalizing this theory to automorphic forms on unitary and symplectic Shimura varieites. In particular, I will introduce certain p-adic analogues of Maass-Shimura weight-raising differential operators, and discuss their action on p-adic automorphic forms, and on the associated mod p Galois representations. In contrast with Serre's classical approach where q-expansions play a prominent role, our approach is geometric in nature and is inspired by earlier work of Katz and Gross.<br />
This talk is based joint work with Eishen, and also with Fintzen--Varma, and with Flander--Ghitza--McAndrew.<br />
<br />
|} <br />
</center><br />
<br />
== March 28==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Adebisi Agboola'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Relative K-groups and rings of integers<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Suppose that F is a number field and G is a finite group. I shall discuss a conjecture in relative algebraic K-theory (in essence, a conjectural Hasse principle applied to certain relative algebraic K-groups) that implies an affirmative answer to both the inverse Galois problem for F and G and to an analogous problem concerning the Galois module structure of rings of integers in tame extensions of F. It also implies the weak Malle conjecture on counting tame G-extensions of F according to discriminant. The K-theoretic conjecture can be proved in many cases (subject to mild technical conditions), e.g. when G is of odd order, giving a partial analogue of a classical theorem of Shafarevich in this setting. While this approach does not, as yet, resolve any new cases of the inverse Galois problem, it does yield substantial new results concerning both the Galois module structure of rings of integers and the weak Malle conjecture.<br />
<br />
|} <br />
</center><br />
<br />
== April 4==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Wei-Lun Tsai'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Hecke L-functions and $\ell$ torsion in class groups<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: The canonical Hecke characters in the sense of Rohrlich form a <br />
set of algebraic Hecke characters with important arithmetic properties.<br />
In this talk, we will explain how one can prove quantitative <br />
nonvanishing results for the central values of their corresponding <br />
L-functions using methods of an arithmetic statistical flavor. In <br />
particular, the methods used rely crucially on recent work of Ellenberg, <br />
Pierce, and Wood concerning bounds for $\ell$-torsion in class groups of <br />
number fields. This is joint work with Byoung Du Kim and Riad Masri.<br />
|} <br />
</center><br />
<br />
== April 11==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Taylor Mcadam'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Almost-prime times in horospherical flows<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Equidistribution results play an important role in dynamical systems and their applications in number theory. Often in such applications it is desirable for equidistribution to be effective (i.e. the rate of convergence is known). In this talk I will discuss some of the history of effective equidistribution results in homogeneous dynamics and give an effective result for horospherical flows on the space of lattices. I will then describe an application to studying the distribution of almost-prime times in horospherical orbits and discuss connections of this work to Sarnak’s Mobius disjointness conjecture.<br />
|} <br />
</center><br />
<br />
== April 18==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Ila Varma'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Malle's Conjecture for octic $D_4$-fields.<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: We consider the family of normal octic fields with Galois group $D_4$, ordered by their discriminant. In forthcoming joint work with Arul Shankar, we verify the strong Malle conjecture for this family of number fields, obtaining the order of growth as well as the constant of proportionality. In this talk, we will discuss and review the combination of techniques from analytic number theory and geometry-of-numbers methods used to prove these results.<br />
|} <br />
</center><br />
<br />
== April 25==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Michael Bush'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Interactions between group theory and number theory<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: I'll survey some of the ways in which group theory has helped us understand extensions of number fields with restricted ramification and why one might care about such things. Some of Nigel's contributions will be highlighted. A good portion of the talk should be accessible to those other than number theorists.<br />
|} <br />
</center><br />
<br />
== April 25==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Rafe Jones'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Eventually stable polynomials and arboreal Galois representations<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Call a polynomial defined over a field K eventually stable if its nth iterate has a uniformly bounded number of irreducible factors (over K) as n grows. I’ll discuss some far-reaching conjectures on eventual stability, and recent work on various special cases. I’ll also describe some natural connections between eventual stability and arboreal Galois representations, which Nigel Boston introduced in the early 2000s. <br />
|} <br />
</center><br />
<br />
==April 25 NTS==<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Jen Berg'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Rational points on conic bundles over elliptic curves with positive rank<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Varieties that fail to have rational points despite having local points for each prime are said to fail the Hasse principle. A systematic tool accounting for these failures is called the Brauer-Manin obstruction, which uses the Brauer group, Br X, to preclude the existence of rational points on a variety X. In this talk, we'll explore the arithmetic of conic bundles over elliptic curves of positive rank over a number field k. We'll discuss the insufficiency of the known obstructions to explain the failures of the Hasse principle for such varieties over a number field. We'll further consider questions on the distribution of the rational points of X with respect to the image of X(k) inside of the rational points of the elliptic curve E. In the process, we'll discuss results on a local-to-global principle for torsion points on elliptic curves over Q. This is joint work in progress with Masahiro Nakahara.<br />
|} <br />
</center><br />
<br />
== April 25==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Judy Walker'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Derangements of Finite Groups<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: In the early 1990’s, Nigel Boston taught an innovative graduate-level group theory course at the University of Illinois that focused on derangements (fixed-point-free elements) of transitive permutation groups. The course culminated in the writing of a 7-authored paper that appeared in Communications in Algebra in 1993. This paper contained a conjecture that was eventually proven by Fulman and Guralnick, with that result appearing in the Transactions of the American Mathematical Society just last year.<br />
|} <br />
</center></div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS&diff=17384NTS2019-04-25T00:38:28Z<p>Rdavis: </p>
<hr />
<div>= Number Theory / Representation Theory Seminar, University of Wisconsin - Madison =<br />
<br />
<br />
*'''When:''' Thursdays, 2:30 PM – 3:30 PM<br />
*'''Where:''' Van Vleck B113<br />
*Please join the [https://mailhost.math.wisc.edu/mailman/listinfo/nts NT/RT mailing list:] (you must be on a math department computer to use this link).<br />
<br />
There is also an accompanying [https://www.math.wisc.edu/wiki/index.php/NTSGrad_Spring_2019 graduate-level seminar], which meets on Tuesdays.<br><br />
<br />
You can find our Fall 2018 speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Fall_2018_Semester Fall 2018].<br />
<br><br />
You can find our previous speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Spring_2018_Semester Spring 2018].<br />
<br />
= Spring 2019 Semester =<br />
<br />
<center><br />
<br />
{| style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" width="300" align="center"|'''Date'''<br />
| bgcolor="#F0A0A0" width="300" align="center"|'''Speaker''' (click for homepage)<br />
| bgcolor="#BCD2EE" width="300" align="center"|'''Title''' (click for abstract)<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 23<br />
'''Wed. Room VV B231'''<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.princeton.edu/~yunqingt/ Yunqing Tang (Princeton University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_23 Reductions of abelian surfaces over global function fields]<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 24<br />
| bgcolor="#F0B0B0" align="center" | Hassan-Mao-Smith--Zhu<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_24 The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Jan 31<br />
| bgcolor="#F0B0B0" align="center" | [https://faculty.math.illinois.edu/~kpratt4/ Kyle Pratt (University of Illinois at Urbana-Champaign)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_31 Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 7 <br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~shamgar/ Shamgar Gurevich (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_7 Harmonic Analysis on $GL_n$ over finite fields] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 14<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~thyang/ Tonghai Yang (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_14 The Lambda invariant and its CM values]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 21<br />
| bgcolor="#F0B0B0" align="center" | No Seminar<br />
| bgcolor="#BCE2FE"|<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 28<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.columbia.edu/~brianrl/ Brian Lawrence (the University of Chicago)] <br />
| bgcolor="#BCE2FE"|[https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_28 Diophantine problems and a p-adic period map.] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 7<br />
| bgcolor="#F0B0B0" align="center" |[https://sites.google.com/view/masoudzargar/ Masoud Zargar (Regensburg)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_7 Sections of quadrics over the affine line] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 14<br />
| bgcolor="#F0B0B0" align="center" | [http://www.its.caltech.edu/~mantovan/ Elena Mantovan (Caltech)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_14 p-adic automorphic forms, differential operators and Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 21<br />
| bgcolor="#F0B0B0" align="center" | Spring Break<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 28<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.ucsb.edu/~agboola/ Adebisi Agboola (UCSB)] <br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_28 Relative K-groups and rings of integers]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 4<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.tamu.edu/~wltsai/ Wei-Lun Tsai (Texas A&M University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_4 Hecke L-functions and $\ell$ torsion in class groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 11<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~tmcadam/ Taylor McAdam (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Almost-prime times in horospherical flows]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 18 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~ila/ Ila Varma (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Malle's Conjecture for octic $D_4$-fields.]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''10:00-11:00 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://bushm.academic.wlu.edu Michael Bush (Washington & Lee)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Interactions between group theory and number theory]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''11:15-12:15 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://people.carleton.edu/~rfjones/ Rafe Jones (Carleton College)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Eventually stable polynomials and arboreal Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | [https://math.rice.edu/~jb93/ Jen Berg (Rice University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25_NTS Rational points on conic bundles over elliptic curves with positive rank] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''4:00-5:00 Room VV B239'''<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.unl.edu/~jwalker7/ Judy Walker (Nebraska)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Derangements of Finite Groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 2<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~mmwood/ Melanie Wood (UW-Madison)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 9 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.mathcs.emory.edu/~dzb/ David Zureick-Brown (Emory College of Arts and Sciences)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
|}<br />
</center><br />
<br />
<br><br />
<br />
*to be confirmed<br />
<br />
= Organizer contact information =<br />
<br />
[http://www.math.wisc.edu/~ntalebiz/ Naser Talebizadeh Sardari]<br />
<br />
[http://www.math.wisc.edu/~shusterman/ Mark Shusterman]<br />
<br />
[http://www.math.wisc.edu/~ruixiang/ Ruixiang Zhang]<br />
----<br />
Return to the [[Algebra|Algebra Group Page]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS_ABSTRACTSpring2019&diff=17381NTS ABSTRACTSpring20192019-04-24T13:45:24Z<p>Rdavis: </p>
<hr />
<div>Return to [https://www.math.wisc.edu/wiki/index.php/NTS ]<br />
<br />
<br />
== Jan 23 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Yunqing Tang '''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Reductions of abelian surfaces over global function fields<br />
|-<br />
| bgcolor="#BCD2EE" | For a non-isotrivial ordinary abelian surface $A$ over a global function field, under mild assumptions, we prove that there are infinitely many places modulo which $A$ is geometrically isogenous to the product of two elliptic curves. This result can be viewed as a generalization of a theorem of Chai and Oort. This is joint work with Davesh Maulik and Ananth Shankar.<br />
<br />
|} <br />
</center><br />
<br />
<br><br />
<br />
== Jan 24 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Hassan-Mao-Smith--Zhu'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Assume a polynomial-time algorithm for factoring integers, Conjecture~\ref{conj}, $d\geq 3,$ and $q$ and $p$ prime numbers, where $p\leq q^A$ for some $A>0$. We develop a polynomial-time algorithm in $\log(q)$ that lifts every $\mathbb{Z}/q\mathbb{Z}$ point of $S^{d-2}\subset S^{d}$ to a $\mathbb{Z}[1/p]$ point of $S^d$ with the minimum height. We implement our algorithm for $d=3 \text{ and }4$. Based on our numerical results, we formulate a conjecture which can be checked in polynomial-time and gives the optimal bound on the diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$. <br />
<br />
|} <br />
</center><br />
<br />
<br />
== Jan 31 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Kyle Pratt'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: I will discuss recent work, joint with Bui, Robles, and Zaharescu, on a moment problem for Dirichlet $L$-functions. By way of motivation I will spend some time discussing the Lindel\"of Hypothesis, and work of Bettin, Chandee, and Radziwi\l\l. The talk will be accessible, as I will give lots of background information and will not dwell on technicalities. <br />
<br />
|} <br />
</center><br />
<br />
== Feb 7 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Shamgar Gurevich'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Harmonic Analysis on $GL_n$ over finite fields<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: There are many formulas that express interesting properties of a group G in terms of sums over its characters.<br />
For evaluating or estimating these sums, one of the most salient quantities to understand is the {\it character ratio}:<br />
$$trace (\rho(g))/dim (\rho),$$<br />
for an irreducible representation $\rho$ of G and an element g of G. For example, Diaconis and Shahshahani stated a formula of this type for analyzing G-biinvariant random walks on G. It turns out that, for classical groups G over finite fields (which provide most examples of finite simple groups), there is a natural invariant of representations that provides strong information on the character ratio. We call this invariant {\it rank}. This talk will discuss the notion of rank for GLn over finite fields, and apply the results to random walks. This is joint work with Roger Howe (TAMU).<br />
<br />
|} <br />
</center><br />
<br />
== Feb 14 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Tonghai Yang'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | The Lambda invariant and its CM values<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: The Lambda invariant which parametrizes elliptic curves with two torsions (X_0(2)) has some interesting properties, some similar to that of the j-invariants, and some not. For example, $\lambda(\frac{d+\sqrt d}2)$ is a unit sometime. In this talk, I will briefly describe some of the properties. This is joint work with Hongbo Yin and Peng Yu.<br />
<br />
|} <br />
</center><br />
<br />
== Feb 28 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Brian Lawrence'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Diophantine problems and a p-adic period map.<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: I will outline a proof of Mordell's conjecture / Faltings's theorem using p-adic Hodge theory. Joint with Akshay Venkatesh.<br />
<br />
|} <br />
</center><br />
<br />
== March 7==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Masoud Zargar'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Sections of quadrics over the affine line<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Abstract: Suppose we have a quadratic form Q(x) in d\geq 4 variables over F_q[t] and f(t) is a polynomial over F_q. We consider the affine variety X given by the equation Q(x)=f(t) as a family of varieties over the affine line A^1_{F_q}. Given finitely many closed points in distinct fibers of this family, we ask when there exists a section passing through these points. We study this problem using the circle method over F_q((1/t)). Time permitting, I will mention connections to Lubotzky-Phillips-Sarnak (LPS) Ramanujan graphs. Joint with Naser T. Sardari<br />
<br />
|} <br />
</center><br />
<br />
== March 14==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Elena Mantovan'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | p-adic automorphic forms, differential operators and Galois representations<br />
|-<br />
| bgcolor="#BCD2EE" | A strategy pioneered by Serre and Katz in the 1970s yields a construction of p-adic families of modular forms via the study of Serre's weight-raising differential operator Theta. This construction is a key ingredient in Deligne-Serre's theorem associating Galois representations to modular forms of weight 1, and in the study of the weight part of Serre's conjecture. In this talk I will discuss recent progress towards generalizing this theory to automorphic forms on unitary and symplectic Shimura varieites. In particular, I will introduce certain p-adic analogues of Maass-Shimura weight-raising differential operators, and discuss their action on p-adic automorphic forms, and on the associated mod p Galois representations. In contrast with Serre's classical approach where q-expansions play a prominent role, our approach is geometric in nature and is inspired by earlier work of Katz and Gross.<br />
This talk is based joint work with Eishen, and also with Fintzen--Varma, and with Flander--Ghitza--McAndrew.<br />
<br />
|} <br />
</center><br />
<br />
== March 28==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Adebisi Agboola'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Relative K-groups and rings of integers<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Suppose that F is a number field and G is a finite group. I shall discuss a conjecture in relative algebraic K-theory (in essence, a conjectural Hasse principle applied to certain relative algebraic K-groups) that implies an affirmative answer to both the inverse Galois problem for F and G and to an analogous problem concerning the Galois module structure of rings of integers in tame extensions of F. It also implies the weak Malle conjecture on counting tame G-extensions of F according to discriminant. The K-theoretic conjecture can be proved in many cases (subject to mild technical conditions), e.g. when G is of odd order, giving a partial analogue of a classical theorem of Shafarevich in this setting. While this approach does not, as yet, resolve any new cases of the inverse Galois problem, it does yield substantial new results concerning both the Galois module structure of rings of integers and the weak Malle conjecture.<br />
<br />
|} <br />
</center><br />
<br />
== April 4==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Wei-Lun Tsai'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Hecke L-functions and $\ell$ torsion in class groups<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: The canonical Hecke characters in the sense of Rohrlich form a <br />
set of algebraic Hecke characters with important arithmetic properties.<br />
In this talk, we will explain how one can prove quantitative <br />
nonvanishing results for the central values of their corresponding <br />
L-functions using methods of an arithmetic statistical flavor. In <br />
particular, the methods used rely crucially on recent work of Ellenberg, <br />
Pierce, and Wood concerning bounds for $\ell$-torsion in class groups of <br />
number fields. This is joint work with Byoung Du Kim and Riad Masri.<br />
|} <br />
</center><br />
<br />
== April 11==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Taylor Mcadam'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Almost-prime times in horospherical flows<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Equidistribution results play an important role in dynamical systems and their applications in number theory. Often in such applications it is desirable for equidistribution to be effective (i.e. the rate of convergence is known). In this talk I will discuss some of the history of effective equidistribution results in homogeneous dynamics and give an effective result for horospherical flows on the space of lattices. I will then describe an application to studying the distribution of almost-prime times in horospherical orbits and discuss connections of this work to Sarnak’s Mobius disjointness conjecture.<br />
|} <br />
</center><br />
<br />
== April 18==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Ila Varma'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Malle's Conjecture for octic $D_4$-fields.<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: We consider the family of normal octic fields with Galois group $D_4$, ordered by their discriminant. In forthcoming joint work with Arul Shankar, we verify the strong Malle conjecture for this family of number fields, obtaining the order of growth as well as the constant of proportionality. In this talk, we will discuss and review the combination of techniques from analytic number theory and geometry-of-numbers methods used to prove these results.<br />
|} <br />
</center><br />
<br />
== April 25==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Rafe Jones'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Eventually stable polynomials and arboreal Galois representations<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Call a polynomial defined over a field K eventually stable if its nth iterate has a uniformly bounded number of irreducible factors (over K) as n grows. I’ll discuss some far-reaching conjectures on eventual stability, and recent work on various special cases. I’ll also describe some natural connections between eventual stability and arboreal Galois representations, which Nigel Boston introduced in the early 2000s. <br />
|} <br />
</center><br />
<br />
==April 25 NTS==<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Jen Berg'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Rational points on conic bundles over elliptic curves with positive rank<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Varieties that fail to have rational points despite having local points for each prime are said to fail the Hasse principle. A systematic tool accounting for these failures is called the Brauer-Manin obstruction, which uses the Brauer group, Br X, to preclude the existence of rational points on a variety X. In this talk, we'll explore the arithmetic of conic bundles over elliptic curves of positive rank over a number field k. We'll discuss the insufficiency of the known obstructions to explain the failures of the Hasse principle for such varieties over a number field. We'll further consider questions on the distribution of the rational points of X with respect to the image of X(k) inside of the rational points of the elliptic curve E. In the process, we'll discuss results on a local-to-global principle for torsion points on elliptic curves over Q. This is joint work in progress with Masahiro Nakahara.<br />
|} <br />
</center></div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS&diff=17380NTS2019-04-24T13:45:11Z<p>Rdavis: </p>
<hr />
<div>= Number Theory / Representation Theory Seminar, University of Wisconsin - Madison =<br />
<br />
<br />
*'''When:''' Thursdays, 2:30 PM – 3:30 PM<br />
*'''Where:''' Van Vleck B113<br />
*Please join the [https://mailhost.math.wisc.edu/mailman/listinfo/nts NT/RT mailing list:] (you must be on a math department computer to use this link).<br />
<br />
There is also an accompanying [https://www.math.wisc.edu/wiki/index.php/NTSGrad_Spring_2019 graduate-level seminar], which meets on Tuesdays.<br><br />
<br />
You can find our Fall 2018 speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Fall_2018_Semester Fall 2018].<br />
<br><br />
You can find our previous speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Spring_2018_Semester Spring 2018].<br />
<br />
= Spring 2019 Semester =<br />
<br />
<center><br />
<br />
{| style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" width="300" align="center"|'''Date'''<br />
| bgcolor="#F0A0A0" width="300" align="center"|'''Speaker''' (click for homepage)<br />
| bgcolor="#BCD2EE" width="300" align="center"|'''Title''' (click for abstract)<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 23<br />
'''Wed. Room VV B231'''<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.princeton.edu/~yunqingt/ Yunqing Tang (Princeton University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_23 Reductions of abelian surfaces over global function fields]<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 24<br />
| bgcolor="#F0B0B0" align="center" | Hassan-Mao-Smith--Zhu<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_24 The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Jan 31<br />
| bgcolor="#F0B0B0" align="center" | [https://faculty.math.illinois.edu/~kpratt4/ Kyle Pratt (University of Illinois at Urbana-Champaign)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_31 Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 7 <br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~shamgar/ Shamgar Gurevich (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_7 Harmonic Analysis on $GL_n$ over finite fields] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 14<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~thyang/ Tonghai Yang (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_14 The Lambda invariant and its CM values]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 21<br />
| bgcolor="#F0B0B0" align="center" | No Seminar<br />
| bgcolor="#BCE2FE"|<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 28<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.columbia.edu/~brianrl/ Brian Lawrence (the University of Chicago)] <br />
| bgcolor="#BCE2FE"|[https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_28 Diophantine problems and a p-adic period map.] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 7<br />
| bgcolor="#F0B0B0" align="center" |[https://sites.google.com/view/masoudzargar/ Masoud Zargar (Regensburg)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_7 Sections of quadrics over the affine line] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 14<br />
| bgcolor="#F0B0B0" align="center" | [http://www.its.caltech.edu/~mantovan/ Elena Mantovan (Caltech)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_14 p-adic automorphic forms, differential operators and Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 21<br />
| bgcolor="#F0B0B0" align="center" | Spring Break<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 28<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.ucsb.edu/~agboola/ Adebisi Agboola (UCSB)] <br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_28 Relative K-groups and rings of integers]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 4<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.tamu.edu/~wltsai/ Wei-Lun Tsai (Texas A&M University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_4 Hecke L-functions and $\ell$ torsion in class groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 11<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~tmcadam/ Taylor McAdam (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Almost-prime times in horospherical flows]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 18 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~ila/ Ila Varma (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Malle's Conjecture for octic $D_4$-fields.]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''10:00-11:00 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://bushm.academic.wlu.edu Michael Bush (Washington & Lee)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''11:15-12:15 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://people.carleton.edu/~rfjones/ Rafe Jones (Carleton College)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Eventually stable polynomials and arboreal Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | [https://math.rice.edu/~jb93/ Jen Berg (Rice University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25NTS Rational points on conic bundles over elliptic curves with positive rank] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''4:00-5:00 Room VV B239'''<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.unl.edu/~jwalker7/ Judy Walker (Nebraska)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 2<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~mmwood/ Melanie Wood (UW-Madison)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 9 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.mathcs.emory.edu/~dzb/ David Zureick-Brown (Emory College of Arts and Sciences)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
|}<br />
</center><br />
<br />
<br><br />
<br />
*to be confirmed<br />
<br />
= Organizer contact information =<br />
<br />
[http://www.math.wisc.edu/~ntalebiz/ Naser Talebizadeh Sardari]<br />
<br />
[http://www.math.wisc.edu/~shusterman/ Mark Shusterman]<br />
<br />
[http://www.math.wisc.edu/~ruixiang/ Ruixiang Zhang]<br />
----<br />
Return to the [[Algebra|Algebra Group Page]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS_ABSTRACTSpring2019&diff=17379NTS ABSTRACTSpring20192019-04-24T13:42:33Z<p>Rdavis: </p>
<hr />
<div>Return to [https://www.math.wisc.edu/wiki/index.php/NTS ]<br />
<br />
<br />
== Jan 23 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Yunqing Tang '''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Reductions of abelian surfaces over global function fields<br />
|-<br />
| bgcolor="#BCD2EE" | For a non-isotrivial ordinary abelian surface $A$ over a global function field, under mild assumptions, we prove that there are infinitely many places modulo which $A$ is geometrically isogenous to the product of two elliptic curves. This result can be viewed as a generalization of a theorem of Chai and Oort. This is joint work with Davesh Maulik and Ananth Shankar.<br />
<br />
|} <br />
</center><br />
<br />
<br><br />
<br />
== Jan 24 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Hassan-Mao-Smith--Zhu'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Assume a polynomial-time algorithm for factoring integers, Conjecture~\ref{conj}, $d\geq 3,$ and $q$ and $p$ prime numbers, where $p\leq q^A$ for some $A>0$. We develop a polynomial-time algorithm in $\log(q)$ that lifts every $\mathbb{Z}/q\mathbb{Z}$ point of $S^{d-2}\subset S^{d}$ to a $\mathbb{Z}[1/p]$ point of $S^d$ with the minimum height. We implement our algorithm for $d=3 \text{ and }4$. Based on our numerical results, we formulate a conjecture which can be checked in polynomial-time and gives the optimal bound on the diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$. <br />
<br />
|} <br />
</center><br />
<br />
<br />
== Jan 31 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Kyle Pratt'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: I will discuss recent work, joint with Bui, Robles, and Zaharescu, on a moment problem for Dirichlet $L$-functions. By way of motivation I will spend some time discussing the Lindel\"of Hypothesis, and work of Bettin, Chandee, and Radziwi\l\l. The talk will be accessible, as I will give lots of background information and will not dwell on technicalities. <br />
<br />
|} <br />
</center><br />
<br />
== Feb 7 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Shamgar Gurevich'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Harmonic Analysis on $GL_n$ over finite fields<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: There are many formulas that express interesting properties of a group G in terms of sums over its characters.<br />
For evaluating or estimating these sums, one of the most salient quantities to understand is the {\it character ratio}:<br />
$$trace (\rho(g))/dim (\rho),$$<br />
for an irreducible representation $\rho$ of G and an element g of G. For example, Diaconis and Shahshahani stated a formula of this type for analyzing G-biinvariant random walks on G. It turns out that, for classical groups G over finite fields (which provide most examples of finite simple groups), there is a natural invariant of representations that provides strong information on the character ratio. We call this invariant {\it rank}. This talk will discuss the notion of rank for GLn over finite fields, and apply the results to random walks. This is joint work with Roger Howe (TAMU).<br />
<br />
|} <br />
</center><br />
<br />
== Feb 14 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Tonghai Yang'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | The Lambda invariant and its CM values<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: The Lambda invariant which parametrizes elliptic curves with two torsions (X_0(2)) has some interesting properties, some similar to that of the j-invariants, and some not. For example, $\lambda(\frac{d+\sqrt d}2)$ is a unit sometime. In this talk, I will briefly describe some of the properties. This is joint work with Hongbo Yin and Peng Yu.<br />
<br />
|} <br />
</center><br />
<br />
== Feb 28 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Brian Lawrence'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Diophantine problems and a p-adic period map.<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: I will outline a proof of Mordell's conjecture / Faltings's theorem using p-adic Hodge theory. Joint with Akshay Venkatesh.<br />
<br />
|} <br />
</center><br />
<br />
== March 7==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Masoud Zargar'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Sections of quadrics over the affine line<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Abstract: Suppose we have a quadratic form Q(x) in d\geq 4 variables over F_q[t] and f(t) is a polynomial over F_q. We consider the affine variety X given by the equation Q(x)=f(t) as a family of varieties over the affine line A^1_{F_q}. Given finitely many closed points in distinct fibers of this family, we ask when there exists a section passing through these points. We study this problem using the circle method over F_q((1/t)). Time permitting, I will mention connections to Lubotzky-Phillips-Sarnak (LPS) Ramanujan graphs. Joint with Naser T. Sardari<br />
<br />
|} <br />
</center><br />
<br />
== March 14==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Elena Mantovan'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | p-adic automorphic forms, differential operators and Galois representations<br />
|-<br />
| bgcolor="#BCD2EE" | A strategy pioneered by Serre and Katz in the 1970s yields a construction of p-adic families of modular forms via the study of Serre's weight-raising differential operator Theta. This construction is a key ingredient in Deligne-Serre's theorem associating Galois representations to modular forms of weight 1, and in the study of the weight part of Serre's conjecture. In this talk I will discuss recent progress towards generalizing this theory to automorphic forms on unitary and symplectic Shimura varieites. In particular, I will introduce certain p-adic analogues of Maass-Shimura weight-raising differential operators, and discuss their action on p-adic automorphic forms, and on the associated mod p Galois representations. In contrast with Serre's classical approach where q-expansions play a prominent role, our approach is geometric in nature and is inspired by earlier work of Katz and Gross.<br />
This talk is based joint work with Eishen, and also with Fintzen--Varma, and with Flander--Ghitza--McAndrew.<br />
<br />
|} <br />
</center><br />
<br />
== March 28==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Adebisi Agboola'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Relative K-groups and rings of integers<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Suppose that F is a number field and G is a finite group. I shall discuss a conjecture in relative algebraic K-theory (in essence, a conjectural Hasse principle applied to certain relative algebraic K-groups) that implies an affirmative answer to both the inverse Galois problem for F and G and to an analogous problem concerning the Galois module structure of rings of integers in tame extensions of F. It also implies the weak Malle conjecture on counting tame G-extensions of F according to discriminant. The K-theoretic conjecture can be proved in many cases (subject to mild technical conditions), e.g. when G is of odd order, giving a partial analogue of a classical theorem of Shafarevich in this setting. While this approach does not, as yet, resolve any new cases of the inverse Galois problem, it does yield substantial new results concerning both the Galois module structure of rings of integers and the weak Malle conjecture.<br />
<br />
|} <br />
</center><br />
<br />
== April 4==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Wei-Lun Tsai'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Hecke L-functions and $\ell$ torsion in class groups<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: The canonical Hecke characters in the sense of Rohrlich form a <br />
set of algebraic Hecke characters with important arithmetic properties.<br />
In this talk, we will explain how one can prove quantitative <br />
nonvanishing results for the central values of their corresponding <br />
L-functions using methods of an arithmetic statistical flavor. In <br />
particular, the methods used rely crucially on recent work of Ellenberg, <br />
Pierce, and Wood concerning bounds for $\ell$-torsion in class groups of <br />
number fields. This is joint work with Byoung Du Kim and Riad Masri.<br />
|} <br />
</center><br />
<br />
== April 11==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Taylor Mcadam'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Almost-prime times in horospherical flows<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Equidistribution results play an important role in dynamical systems and their applications in number theory. Often in such applications it is desirable for equidistribution to be effective (i.e. the rate of convergence is known). In this talk I will discuss some of the history of effective equidistribution results in homogeneous dynamics and give an effective result for horospherical flows on the space of lattices. I will then describe an application to studying the distribution of almost-prime times in horospherical orbits and discuss connections of this work to Sarnak’s Mobius disjointness conjecture.<br />
|} <br />
</center><br />
<br />
== April 18==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Ila Varma'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Malle's Conjecture for octic $D_4$-fields.<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: We consider the family of normal octic fields with Galois group $D_4$, ordered by their discriminant. In forthcoming joint work with Arul Shankar, we verify the strong Malle conjecture for this family of number fields, obtaining the order of growth as well as the constant of proportionality. In this talk, we will discuss and review the combination of techniques from analytic number theory and geometry-of-numbers methods used to prove these results.<br />
|} <br />
</center><br />
<br />
== April 25==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Rafe Jones'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Eventually stable polynomials and arboreal Galois representations<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Call a polynomial defined over a field K eventually stable if its nth iterate has a uniformly bounded number of irreducible factors (over K) as n grows. I’ll discuss some far-reaching conjectures on eventual stability, and recent work on various special cases. I’ll also describe some natural connections between eventual stability and arboreal Galois representations, which Nigel Boston introduced in the early 2000s. <br />
|} <br />
</center><br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Jen Berg'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Rational points on conic bundles over elliptic curves with positive rank<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Varieties that fail to have rational points despite having local points for each prime are said to fail the Hasse principle. A systematic tool accounting for these failures is called the Brauer-Manin obstruction, which uses the Brauer group, Br X, to preclude the existence of rational points on a variety X. In this talk, we'll explore the arithmetic of conic bundles over elliptic curves of positive rank over a number field k. We'll discuss the insufficiency of the known obstructions to explain the failures of the Hasse principle for such varieties over a number field. We'll further consider questions on the distribution of the rational points of X with respect to the image of X(k) inside of the rational points of the elliptic curve E. In the process, we'll discuss results on a local-to-global principle for torsion points on elliptic curves over Q. This is joint work in progress with Masahiro Nakahara.<br />
|} <br />
</center></div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS&diff=17369NTS2019-04-22T18:44:51Z<p>Rdavis: </p>
<hr />
<div>= Number Theory / Representation Theory Seminar, University of Wisconsin - Madison =<br />
<br />
<br />
*'''When:''' Thursdays, 2:30 PM – 3:30 PM<br />
*'''Where:''' Van Vleck B113<br />
*Please join the [https://mailhost.math.wisc.edu/mailman/listinfo/nts NT/RT mailing list:] (you must be on a math department computer to use this link).<br />
<br />
There is also an accompanying [https://www.math.wisc.edu/wiki/index.php/NTSGrad_Spring_2019 graduate-level seminar], which meets on Tuesdays.<br><br />
<br />
You can find our Fall 2018 speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Fall_2018_Semester Fall 2018].<br />
<br><br />
You can find our previous speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Spring_2018_Semester Spring 2018].<br />
<br />
= Spring 2019 Semester =<br />
<br />
<center><br />
<br />
{| style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" width="300" align="center"|'''Date'''<br />
| bgcolor="#F0A0A0" width="300" align="center"|'''Speaker''' (click for homepage)<br />
| bgcolor="#BCD2EE" width="300" align="center"|'''Title''' (click for abstract)<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 23<br />
'''Wed. Room VV B231'''<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.princeton.edu/~yunqingt/ Yunqing Tang (Princeton University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_23 Reductions of abelian surfaces over global function fields]<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 24<br />
| bgcolor="#F0B0B0" align="center" | Hassan-Mao-Smith--Zhu<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_24 The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Jan 31<br />
| bgcolor="#F0B0B0" align="center" | [https://faculty.math.illinois.edu/~kpratt4/ Kyle Pratt (University of Illinois at Urbana-Champaign)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_31 Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 7 <br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~shamgar/ Shamgar Gurevich (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_7 Harmonic Analysis on $GL_n$ over finite fields] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 14<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~thyang/ Tonghai Yang (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_14 The Lambda invariant and its CM values]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 21<br />
| bgcolor="#F0B0B0" align="center" | No Seminar<br />
| bgcolor="#BCE2FE"|<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 28<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.columbia.edu/~brianrl/ Brian Lawrence (the University of Chicago)] <br />
| bgcolor="#BCE2FE"|[https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_28 Diophantine problems and a p-adic period map.] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 7<br />
| bgcolor="#F0B0B0" align="center" |[https://sites.google.com/view/masoudzargar/ Masoud Zargar (Regensburg)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_7 Sections of quadrics over the affine line] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 14<br />
| bgcolor="#F0B0B0" align="center" | [http://www.its.caltech.edu/~mantovan/ Elena Mantovan (Caltech)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_14 p-adic automorphic forms, differential operators and Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 21<br />
| bgcolor="#F0B0B0" align="center" | Spring Break<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 28<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.ucsb.edu/~agboola/ Adebisi Agboola (UCSB)] <br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_28 Relative K-groups and rings of integers]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 4<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.tamu.edu/~wltsai/ Wei-Lun Tsai (Texas A&M University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_4 Hecke L-functions and $\ell$ torsion in class groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 11<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~tmcadam/ Taylor McAdam (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Almost-prime times in horospherical flows]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 18 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~ila/ Ila Varma (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Malle's Conjecture for octic $D_4$-fields.]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''10:00-11:00 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://bushm.academic.wlu.edu Michael Bush (Washington & Lee)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''11:15-12:15 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://people.carleton.edu/~rfjones/ Rafe Jones (Carleton College)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Eventually stable polynomials and arboreal Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | [https://math.rice.edu/~jb93/ Jen Berg (Rice University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jen Rational points on conic bundles over elliptic curves with positive rank] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''4:00-5:00 Room VV B239'''<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.unl.edu/~jwalker7/ Judy Walker (Nebraska)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 2<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~mmwood/ Melanie Wood (UW-Madison)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 9 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.mathcs.emory.edu/~dzb/ David Zureick-Brown (Emory College of Arts and Sciences)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
|}<br />
</center><br />
<br />
<br><br />
<br />
*to be confirmed<br />
<br />
= Organizer contact information =<br />
<br />
[http://www.math.wisc.edu/~ntalebiz/ Naser Talebizadeh Sardari]<br />
<br />
[http://www.math.wisc.edu/~shusterman/ Mark Shusterman]<br />
<br />
[http://www.math.wisc.edu/~ruixiang/ Ruixiang Zhang]<br />
----<br />
Return to the [[Algebra|Algebra Group Page]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS_ABSTRACTSpring2019&diff=17365NTS ABSTRACTSpring20192019-04-22T14:00:20Z<p>Rdavis: </p>
<hr />
<div>Return to [https://www.math.wisc.edu/wiki/index.php/NTS ]<br />
<br />
<br />
== Jan 23 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Yunqing Tang '''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Reductions of abelian surfaces over global function fields<br />
|-<br />
| bgcolor="#BCD2EE" | For a non-isotrivial ordinary abelian surface $A$ over a global function field, under mild assumptions, we prove that there are infinitely many places modulo which $A$ is geometrically isogenous to the product of two elliptic curves. This result can be viewed as a generalization of a theorem of Chai and Oort. This is joint work with Davesh Maulik and Ananth Shankar.<br />
<br />
|} <br />
</center><br />
<br />
<br><br />
<br />
== Jan 24 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Hassan-Mao-Smith--Zhu'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Assume a polynomial-time algorithm for factoring integers, Conjecture~\ref{conj}, $d\geq 3,$ and $q$ and $p$ prime numbers, where $p\leq q^A$ for some $A>0$. We develop a polynomial-time algorithm in $\log(q)$ that lifts every $\mathbb{Z}/q\mathbb{Z}$ point of $S^{d-2}\subset S^{d}$ to a $\mathbb{Z}[1/p]$ point of $S^d$ with the minimum height. We implement our algorithm for $d=3 \text{ and }4$. Based on our numerical results, we formulate a conjecture which can be checked in polynomial-time and gives the optimal bound on the diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$. <br />
<br />
|} <br />
</center><br />
<br />
<br />
== Jan 31 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Kyle Pratt'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: I will discuss recent work, joint with Bui, Robles, and Zaharescu, on a moment problem for Dirichlet $L$-functions. By way of motivation I will spend some time discussing the Lindel\"of Hypothesis, and work of Bettin, Chandee, and Radziwi\l\l. The talk will be accessible, as I will give lots of background information and will not dwell on technicalities. <br />
<br />
|} <br />
</center><br />
<br />
== Feb 7 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Shamgar Gurevich'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Harmonic Analysis on $GL_n$ over finite fields<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: There are many formulas that express interesting properties of a group G in terms of sums over its characters.<br />
For evaluating or estimating these sums, one of the most salient quantities to understand is the {\it character ratio}:<br />
$$trace (\rho(g))/dim (\rho),$$<br />
for an irreducible representation $\rho$ of G and an element g of G. For example, Diaconis and Shahshahani stated a formula of this type for analyzing G-biinvariant random walks on G. It turns out that, for classical groups G over finite fields (which provide most examples of finite simple groups), there is a natural invariant of representations that provides strong information on the character ratio. We call this invariant {\it rank}. This talk will discuss the notion of rank for GLn over finite fields, and apply the results to random walks. This is joint work with Roger Howe (TAMU).<br />
<br />
|} <br />
</center><br />
<br />
== Feb 14 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Tonghai Yang'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | The Lambda invariant and its CM values<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: The Lambda invariant which parametrizes elliptic curves with two torsions (X_0(2)) has some interesting properties, some similar to that of the j-invariants, and some not. For example, $\lambda(\frac{d+\sqrt d}2)$ is a unit sometime. In this talk, I will briefly describe some of the properties. This is joint work with Hongbo Yin and Peng Yu.<br />
<br />
|} <br />
</center><br />
<br />
== Feb 28 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Brian Lawrence'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Diophantine problems and a p-adic period map.<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: I will outline a proof of Mordell's conjecture / Faltings's theorem using p-adic Hodge theory. Joint with Akshay Venkatesh.<br />
<br />
|} <br />
</center><br />
<br />
== March 7==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Masoud Zargar'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Sections of quadrics over the affine line<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Abstract: Suppose we have a quadratic form Q(x) in d\geq 4 variables over F_q[t] and f(t) is a polynomial over F_q. We consider the affine variety X given by the equation Q(x)=f(t) as a family of varieties over the affine line A^1_{F_q}. Given finitely many closed points in distinct fibers of this family, we ask when there exists a section passing through these points. We study this problem using the circle method over F_q((1/t)). Time permitting, I will mention connections to Lubotzky-Phillips-Sarnak (LPS) Ramanujan graphs. Joint with Naser T. Sardari<br />
<br />
|} <br />
</center><br />
<br />
== March 14==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Elena Mantovan'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | p-adic automorphic forms, differential operators and Galois representations<br />
|-<br />
| bgcolor="#BCD2EE" | A strategy pioneered by Serre and Katz in the 1970s yields a construction of p-adic families of modular forms via the study of Serre's weight-raising differential operator Theta. This construction is a key ingredient in Deligne-Serre's theorem associating Galois representations to modular forms of weight 1, and in the study of the weight part of Serre's conjecture. In this talk I will discuss recent progress towards generalizing this theory to automorphic forms on unitary and symplectic Shimura varieites. In particular, I will introduce certain p-adic analogues of Maass-Shimura weight-raising differential operators, and discuss their action on p-adic automorphic forms, and on the associated mod p Galois representations. In contrast with Serre's classical approach where q-expansions play a prominent role, our approach is geometric in nature and is inspired by earlier work of Katz and Gross.<br />
This talk is based joint work with Eishen, and also with Fintzen--Varma, and with Flander--Ghitza--McAndrew.<br />
<br />
|} <br />
</center><br />
<br />
== March 28==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Adebisi Agboola'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Relative K-groups and rings of integers<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Suppose that F is a number field and G is a finite group. I shall discuss a conjecture in relative algebraic K-theory (in essence, a conjectural Hasse principle applied to certain relative algebraic K-groups) that implies an affirmative answer to both the inverse Galois problem for F and G and to an analogous problem concerning the Galois module structure of rings of integers in tame extensions of F. It also implies the weak Malle conjecture on counting tame G-extensions of F according to discriminant. The K-theoretic conjecture can be proved in many cases (subject to mild technical conditions), e.g. when G is of odd order, giving a partial analogue of a classical theorem of Shafarevich in this setting. While this approach does not, as yet, resolve any new cases of the inverse Galois problem, it does yield substantial new results concerning both the Galois module structure of rings of integers and the weak Malle conjecture.<br />
<br />
|} <br />
</center><br />
<br />
== April 4==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Wei-Lun Tsai'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Hecke L-functions and $\ell$ torsion in class groups<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: The canonical Hecke characters in the sense of Rohrlich form a <br />
set of algebraic Hecke characters with important arithmetic properties.<br />
In this talk, we will explain how one can prove quantitative <br />
nonvanishing results for the central values of their corresponding <br />
L-functions using methods of an arithmetic statistical flavor. In <br />
particular, the methods used rely crucially on recent work of Ellenberg, <br />
Pierce, and Wood concerning bounds for $\ell$-torsion in class groups of <br />
number fields. This is joint work with Byoung Du Kim and Riad Masri.<br />
|} <br />
</center><br />
<br />
== April 11==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Taylor Mcadam'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Almost-prime times in horospherical flows<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Equidistribution results play an important role in dynamical systems and their applications in number theory. Often in such applications it is desirable for equidistribution to be effective (i.e. the rate of convergence is known). In this talk I will discuss some of the history of effective equidistribution results in homogeneous dynamics and give an effective result for horospherical flows on the space of lattices. I will then describe an application to studying the distribution of almost-prime times in horospherical orbits and discuss connections of this work to Sarnak’s Mobius disjointness conjecture.<br />
|} <br />
</center><br />
<br />
== April 18==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Ila Varma'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Malle's Conjecture for octic $D_4$-fields.<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: We consider the family of normal octic fields with Galois group $D_4$, ordered by their discriminant. In forthcoming joint work with Arul Shankar, we verify the strong Malle conjecture for this family of number fields, obtaining the order of growth as well as the constant of proportionality. In this talk, we will discuss and review the combination of techniques from analytic number theory and geometry-of-numbers methods used to prove these results.<br />
|} <br />
</center><br />
<br />
== April 25==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Rafe Jones'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" |Eventually stable polynomials and arboreal Galois representations<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Call a polynomial defined over a field K eventually stable if its nth iterate has a uniformly bounded number of irreducible factors (over K) as n grows. I’ll discuss some far-reaching conjectures on eventual stability, and recent work on various special cases. I’ll also describe some natural connections between eventual stability and arboreal Galois representations, which Nigel Boston introduced in the early 2000s. <br />
|} <br />
</center></div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS&diff=17364NTS2019-04-22T13:58:53Z<p>Rdavis: </p>
<hr />
<div>= Number Theory / Representation Theory Seminar, University of Wisconsin - Madison =<br />
<br />
<br />
*'''When:''' Thursdays, 2:30 PM – 3:30 PM<br />
*'''Where:''' Van Vleck B113<br />
*Please join the [https://mailhost.math.wisc.edu/mailman/listinfo/nts NT/RT mailing list:] (you must be on a math department computer to use this link).<br />
<br />
There is also an accompanying [https://www.math.wisc.edu/wiki/index.php/NTSGrad_Spring_2019 graduate-level seminar], which meets on Tuesdays.<br><br />
<br />
You can find our Fall 2018 speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Fall_2018_Semester Fall 2018].<br />
<br><br />
You can find our previous speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Spring_2018_Semester Spring 2018].<br />
<br />
= Spring 2019 Semester =<br />
<br />
<center><br />
<br />
{| style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" width="300" align="center"|'''Date'''<br />
| bgcolor="#F0A0A0" width="300" align="center"|'''Speaker''' (click for homepage)<br />
| bgcolor="#BCD2EE" width="300" align="center"|'''Title''' (click for abstract)<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 23<br />
'''Wed. Room VV B231'''<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.princeton.edu/~yunqingt/ Yunqing Tang (Princeton University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_23 Reductions of abelian surfaces over global function fields]<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 24<br />
| bgcolor="#F0B0B0" align="center" | Hassan-Mao-Smith--Zhu<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_24 The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Jan 31<br />
| bgcolor="#F0B0B0" align="center" | [https://faculty.math.illinois.edu/~kpratt4/ Kyle Pratt (University of Illinois at Urbana-Champaign)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_31 Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 7 <br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~shamgar/ Shamgar Gurevich (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_7 Harmonic Analysis on $GL_n$ over finite fields] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 14<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~thyang/ Tonghai Yang (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_14 The Lambda invariant and its CM values]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 21<br />
| bgcolor="#F0B0B0" align="center" | No Seminar<br />
| bgcolor="#BCE2FE"|<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 28<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.columbia.edu/~brianrl/ Brian Lawrence (the University of Chicago)] <br />
| bgcolor="#BCE2FE"|[https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_28 Diophantine problems and a p-adic period map.] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 7<br />
| bgcolor="#F0B0B0" align="center" |[https://sites.google.com/view/masoudzargar/ Masoud Zargar (Regensburg)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_7 Sections of quadrics over the affine line] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 14<br />
| bgcolor="#F0B0B0" align="center" | [http://www.its.caltech.edu/~mantovan/ Elena Mantovan (Caltech)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_14 p-adic automorphic forms, differential operators and Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 21<br />
| bgcolor="#F0B0B0" align="center" | Spring Break<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 28<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.ucsb.edu/~agboola/ Adebisi Agboola (UCSB)] <br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_28 Relative K-groups and rings of integers]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 4<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.tamu.edu/~wltsai/ Wei-Lun Tsai (Texas A&M University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_4 Hecke L-functions and $\ell$ torsion in class groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 11<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~tmcadam/ Taylor McAdam (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Almost-prime times in horospherical flows]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 18 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~ila/ Ila Varma (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Malle's Conjecture for octic $D_4$-fields.]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''10:00-11:00 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://bushm.academic.wlu.edu Michael Bush (Washington & Lee)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''11:15-12:15 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://people.carleton.edu/~rfjones/ Rafe Jones (Carleton College)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Nigel_2 Eventually stable polynomials and arboreal Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | [https://math.rice.edu/~jb93/ Jen Berg (Rice University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Rational points on conic bundles over elliptic curves with positive rank] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''4:00-5:00 Room VV B239'''<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.unl.edu/~jwalker7/ Judy Walker (Nebraska)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 2<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~mmwood/ Melanie Wood (UW-Madison)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 9 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.mathcs.emory.edu/~dzb/ David Zureick-Brown (Emory College of Arts and Sciences)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
|}<br />
</center><br />
<br />
<br><br />
<br />
*to be confirmed<br />
<br />
= Organizer contact information =<br />
<br />
[http://www.math.wisc.edu/~ntalebiz/ Naser Talebizadeh Sardari]<br />
<br />
[http://www.math.wisc.edu/~shusterman/ Mark Shusterman]<br />
<br />
[http://www.math.wisc.edu/~ruixiang/ Ruixiang Zhang]<br />
----<br />
Return to the [[Algebra|Algebra Group Page]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS&diff=17363NTS2019-04-22T13:56:49Z<p>Rdavis: </p>
<hr />
<div>= Number Theory / Representation Theory Seminar, University of Wisconsin - Madison =<br />
<br />
<br />
*'''When:''' Thursdays, 2:30 PM – 3:30 PM<br />
*'''Where:''' Van Vleck B113<br />
*Please join the [https://mailhost.math.wisc.edu/mailman/listinfo/nts NT/RT mailing list:] (you must be on a math department computer to use this link).<br />
<br />
There is also an accompanying [https://www.math.wisc.edu/wiki/index.php/NTSGrad_Spring_2019 graduate-level seminar], which meets on Tuesdays.<br><br />
<br />
You can find our Fall 2018 speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Fall_2018_Semester Fall 2018].<br />
<br><br />
You can find our previous speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Spring_2018_Semester Spring 2018].<br />
<br />
= Spring 2019 Semester =<br />
<br />
<center><br />
<br />
{| style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" width="300" align="center"|'''Date'''<br />
| bgcolor="#F0A0A0" width="300" align="center"|'''Speaker''' (click for homepage)<br />
| bgcolor="#BCD2EE" width="300" align="center"|'''Title''' (click for abstract)<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 23<br />
'''Wed. Room VV B231'''<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.princeton.edu/~yunqingt/ Yunqing Tang (Princeton University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_23 Reductions of abelian surfaces over global function fields]<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 24<br />
| bgcolor="#F0B0B0" align="center" | Hassan-Mao-Smith--Zhu<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_24 The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Jan 31<br />
| bgcolor="#F0B0B0" align="center" | [https://faculty.math.illinois.edu/~kpratt4/ Kyle Pratt (University of Illinois at Urbana-Champaign)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_31 Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 7 <br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~shamgar/ Shamgar Gurevich (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_7 Harmonic Analysis on $GL_n$ over finite fields] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 14<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~thyang/ Tonghai Yang (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_14 The Lambda invariant and its CM values]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 21<br />
| bgcolor="#F0B0B0" align="center" | No Seminar<br />
| bgcolor="#BCE2FE"|<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 28<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.columbia.edu/~brianrl/ Brian Lawrence (the University of Chicago)] <br />
| bgcolor="#BCE2FE"|[https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_28 Diophantine problems and a p-adic period map.] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 7<br />
| bgcolor="#F0B0B0" align="center" |[https://sites.google.com/view/masoudzargar/ Masoud Zargar (Regensburg)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_7 Sections of quadrics over the affine line] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 14<br />
| bgcolor="#F0B0B0" align="center" | [http://www.its.caltech.edu/~mantovan/ Elena Mantovan (Caltech)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_14 p-adic automorphic forms, differential operators and Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 21<br />
| bgcolor="#F0B0B0" align="center" | Spring Break<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 28<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.ucsb.edu/~agboola/ Adebisi Agboola (UCSB)] <br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_28 Relative K-groups and rings of integers]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 4<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.tamu.edu/~wltsai/ Wei-Lun Tsai (Texas A&M University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_4 Hecke L-functions and $\ell$ torsion in class groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 11<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~tmcadam/ Taylor McAdam (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Almost-prime times in horospherical flows]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 18 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~ila/ Ila Varma (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Malle's Conjecture for octic $D_4$-fields.]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''10:00-11:00 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://bushm.academic.wlu.edu Michael Bush (Washington & Lee)]<br />
| bgcolor="#BCE2FE"| [] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''11:15-12:15 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://people.carleton.edu/~rfjones/ Rafe Jones (Carleton College)]<br />
| bgcolor="#BCE2FE"| [] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | [https://math.rice.edu/~jb93/ Jen Berg (Rice University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Rational points on conic bundles over elliptic curves with positive rank] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''4:00-5:00 Room VV B239'''<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.unl.edu/~jwalker7/ Judy Walker (Nebraska)]<br />
| bgcolor="#BCE2FE"| [] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 2<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~mmwood/ Melanie Wood (UW-Madison)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 9 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.mathcs.emory.edu/~dzb/ David Zureick-Brown (Emory College of Arts and Sciences)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
|}<br />
</center><br />
<br />
<br><br />
<br />
*to be confirmed<br />
<br />
= Organizer contact information =<br />
<br />
[http://www.math.wisc.edu/~ntalebiz/ Naser Talebizadeh Sardari]<br />
<br />
[http://www.math.wisc.edu/~shusterman/ Mark Shusterman]<br />
<br />
[http://www.math.wisc.edu/~ruixiang/ Ruixiang Zhang]<br />
----<br />
Return to the [[Algebra|Algebra Group Page]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS&diff=17362NTS2019-04-22T13:55:16Z<p>Rdavis: </p>
<hr />
<div>= Number Theory / Representation Theory Seminar, University of Wisconsin - Madison =<br />
<br />
<br />
*'''When:''' Thursdays, 2:30 PM – 3:30 PM<br />
*'''Where:''' Van Vleck B113<br />
*Please join the [https://mailhost.math.wisc.edu/mailman/listinfo/nts NT/RT mailing list:] (you must be on a math department computer to use this link).<br />
<br />
There is also an accompanying [https://www.math.wisc.edu/wiki/index.php/NTSGrad_Spring_2019 graduate-level seminar], which meets on Tuesdays.<br><br />
<br />
You can find our Fall 2018 speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Fall_2018_Semester Fall 2018].<br />
<br><br />
You can find our previous speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Spring_2018_Semester Spring 2018].<br />
<br />
= Spring 2019 Semester =<br />
<br />
<center><br />
<br />
{| style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" width="300" align="center"|'''Date'''<br />
| bgcolor="#F0A0A0" width="300" align="center"|'''Speaker''' (click for homepage)<br />
| bgcolor="#BCD2EE" width="300" align="center"|'''Title''' (click for abstract)<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 23<br />
'''Wed. Room VV B231'''<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.princeton.edu/~yunqingt/ Yunqing Tang (Princeton University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_23 Reductions of abelian surfaces over global function fields]<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 24<br />
| bgcolor="#F0B0B0" align="center" | Hassan-Mao-Smith--Zhu<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_24 The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Jan 31<br />
| bgcolor="#F0B0B0" align="center" | [https://faculty.math.illinois.edu/~kpratt4/ Kyle Pratt (University of Illinois at Urbana-Champaign)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_31 Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 7 <br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~shamgar/ Shamgar Gurevich (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_7 Harmonic Analysis on $GL_n$ over finite fields] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 14<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~thyang/ Tonghai Yang (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_14 The Lambda invariant and its CM values]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 21<br />
| bgcolor="#F0B0B0" align="center" | No Seminar<br />
| bgcolor="#BCE2FE"|<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 28<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.columbia.edu/~brianrl/ Brian Lawrence (the University of Chicago)] <br />
| bgcolor="#BCE2FE"|[https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_28 Diophantine problems and a p-adic period map.] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 7<br />
| bgcolor="#F0B0B0" align="center" |[https://sites.google.com/view/masoudzargar/ Masoud Zargar (Regensburg)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_7 Sections of quadrics over the affine line] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 14<br />
| bgcolor="#F0B0B0" align="center" | [http://www.its.caltech.edu/~mantovan/ Elena Mantovan (Caltech)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_14 p-adic automorphic forms, differential operators and Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 21<br />
| bgcolor="#F0B0B0" align="center" | Spring Break<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 28<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.ucsb.edu/~agboola/ Adebisi Agboola (UCSB)] <br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_28 Relative K-groups and rings of integers]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 4<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.tamu.edu/~wltsai/ Wei-Lun Tsai (Texas A&M University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_4 Hecke L-functions and $\ell$ torsion in class groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 11<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~tmcadam/ Taylor McAdam (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Almost-prime times in horospherical flows]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 18 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~ila/ Ila Varma (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Malle's Conjecture for octic $D_4$-fields.]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''10:00-11:00 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | [https://bushm.academic.wlu.edu Michael Bush (Washington & Lee)]<br />
| bgcolor="#BCE2FE"| [] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''11:15-12:15 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | []<br />
| bgcolor="#BCE2FE"| [] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | [https://math.rice.edu/~jb93/ Jen Berg (Rice University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Rational points on conic bundles over elliptic curves with positive rank] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''4:00-5:00 Room VV B239'''<br />
| bgcolor="#F0B0B0" align="center" | []<br />
| bgcolor="#BCE2FE"| [] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 2<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~mmwood/ Melanie Wood (UW-Madison)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 9 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.mathcs.emory.edu/~dzb/ David Zureick-Brown (Emory College of Arts and Sciences)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
|}<br />
</center><br />
<br />
<br><br />
<br />
*to be confirmed<br />
<br />
= Organizer contact information =<br />
<br />
[http://www.math.wisc.edu/~ntalebiz/ Naser Talebizadeh Sardari]<br />
<br />
[http://www.math.wisc.edu/~shusterman/ Mark Shusterman]<br />
<br />
[http://www.math.wisc.edu/~ruixiang/ Ruixiang Zhang]<br />
----<br />
Return to the [[Algebra|Algebra Group Page]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS&diff=17361NTS2019-04-22T13:52:22Z<p>Rdavis: </p>
<hr />
<div>= Number Theory / Representation Theory Seminar, University of Wisconsin - Madison =<br />
<br />
<br />
*'''When:''' Thursdays, 2:30 PM – 3:30 PM<br />
*'''Where:''' Van Vleck B113<br />
*Please join the [https://mailhost.math.wisc.edu/mailman/listinfo/nts NT/RT mailing list:] (you must be on a math department computer to use this link).<br />
<br />
There is also an accompanying [https://www.math.wisc.edu/wiki/index.php/NTSGrad_Spring_2019 graduate-level seminar], which meets on Tuesdays.<br><br />
<br />
You can find our Fall 2018 speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Fall_2018_Semester Fall 2018].<br />
<br><br />
You can find our previous speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Spring_2018_Semester Spring 2018].<br />
<br />
= Spring 2019 Semester =<br />
<br />
<center><br />
<br />
{| style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" width="300" align="center"|'''Date'''<br />
| bgcolor="#F0A0A0" width="300" align="center"|'''Speaker''' (click for homepage)<br />
| bgcolor="#BCD2EE" width="300" align="center"|'''Title''' (click for abstract)<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 23<br />
'''Wed. Room VV B231'''<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.princeton.edu/~yunqingt/ Yunqing Tang (Princeton University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_23 Reductions of abelian surfaces over global function fields]<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 24<br />
| bgcolor="#F0B0B0" align="center" | Hassan-Mao-Smith--Zhu<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_24 The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Jan 31<br />
| bgcolor="#F0B0B0" align="center" | [https://faculty.math.illinois.edu/~kpratt4/ Kyle Pratt (University of Illinois at Urbana-Champaign)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_31 Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 7 <br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~shamgar/ Shamgar Gurevich (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_7 Harmonic Analysis on $GL_n$ over finite fields] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 14<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~thyang/ Tonghai Yang (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_14 The Lambda invariant and its CM values]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 21<br />
| bgcolor="#F0B0B0" align="center" | No Seminar<br />
| bgcolor="#BCE2FE"|<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 28<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.columbia.edu/~brianrl/ Brian Lawrence (the University of Chicago)] <br />
| bgcolor="#BCE2FE"|[https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_28 Diophantine problems and a p-adic period map.] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 7<br />
| bgcolor="#F0B0B0" align="center" |[https://sites.google.com/view/masoudzargar/ Masoud Zargar (Regensburg)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_7 Sections of quadrics over the affine line] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 14<br />
| bgcolor="#F0B0B0" align="center" | [http://www.its.caltech.edu/~mantovan/ Elena Mantovan (Caltech)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_14 p-adic automorphic forms, differential operators and Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 21<br />
| bgcolor="#F0B0B0" align="center" | Spring Break<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 28<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.ucsb.edu/~agboola/ Adebisi Agboola (UCSB)] <br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_28 Relative K-groups and rings of integers]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 4<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.tamu.edu/~wltsai/ Wei-Lun Tsai (Texas A&M University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_4 Hecke L-functions and $\ell$ torsion in class groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 11<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~tmcadam/ Taylor McAdam (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Almost-prime times in horospherical flows]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 18 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~ila/ Ila Varma (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Malle's Conjecture for octic $D_4$-fields.]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''10:00-11:00 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | ]<br />
| bgcolor="#BCE2FE"| [] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''11:15-12:15 Room VV 911'''<br />
| bgcolor="#F0B0B0" align="center" | []<br />
| bgcolor="#BCE2FE"| [] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | [https://math.rice.edu/~jb93/ Jen Berg (Rice University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Rational points on conic bundles over elliptic curves with positive rank] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
'''4:00-5:00 Room VV B239'''<br />
| bgcolor="#F0B0B0" align="center" | []<br />
| bgcolor="#BCE2FE"| [] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 2<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~mmwood/ Melanie Wood (UW-Madison)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 9 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.mathcs.emory.edu/~dzb/ David Zureick-Brown (Emory College of Arts and Sciences)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
|}<br />
</center><br />
<br />
<br><br />
<br />
*to be confirmed<br />
<br />
= Organizer contact information =<br />
<br />
[http://www.math.wisc.edu/~ntalebiz/ Naser Talebizadeh Sardari]<br />
<br />
[http://www.math.wisc.edu/~shusterman/ Mark Shusterman]<br />
<br />
[http://www.math.wisc.edu/~ruixiang/ Ruixiang Zhang]<br />
----<br />
Return to the [[Algebra|Algebra Group Page]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS&diff=17360NTS2019-04-22T13:50:43Z<p>Rdavis: </p>
<hr />
<div>= Number Theory / Representation Theory Seminar, University of Wisconsin - Madison =<br />
<br />
<br />
*'''When:''' Thursdays, 2:30 PM – 3:30 PM<br />
*'''Where:''' Van Vleck B113<br />
*Please join the [https://mailhost.math.wisc.edu/mailman/listinfo/nts NT/RT mailing list:] (you must be on a math department computer to use this link).<br />
<br />
There is also an accompanying [https://www.math.wisc.edu/wiki/index.php/NTSGrad_Spring_2019 graduate-level seminar], which meets on Tuesdays.<br><br />
<br />
You can find our Fall 2018 speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Fall_2018_Semester Fall 2018].<br />
<br><br />
You can find our previous speakers in [https://www.math.wisc.edu/wiki/index.php/NTS_Spring_2018_Semester Spring 2018].<br />
<br />
= Spring 2019 Semester =<br />
<br />
<center><br />
<br />
{| style="color:black; font-size:120%" border="0" cellpadding="14" cellspacing="5"<br />
|-<br />
| bgcolor="#D0D0D0" width="300" align="center"|'''Date'''<br />
| bgcolor="#F0A0A0" width="300" align="center"|'''Speaker''' (click for homepage)<br />
| bgcolor="#BCD2EE" width="300" align="center"|'''Title''' (click for abstract)<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 23<br />
'''Wed. Room VV B231'''<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.princeton.edu/~yunqingt/ Yunqing Tang (Princeton University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_23 Reductions of abelian surfaces over global function fields]<br />
|-<br />
| bgcolor="#E0E0E0" align="center" | Jan 24<br />
| bgcolor="#F0B0B0" align="center" | Hassan-Mao-Smith--Zhu<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_24 The diophantine exponent of the $\mathbb{Z}/q\mathbb{Z}$ points of $S^{d-2}\subset S^d$]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Jan 31<br />
| bgcolor="#F0B0B0" align="center" | [https://faculty.math.illinois.edu/~kpratt4/ Kyle Pratt (University of Illinois at Urbana-Champaign)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Jan_31 Breaking the $\frac{1}{2}$-barrier for the twisted second moment of Dirichlet $L$-functions]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 7 <br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~shamgar/ Shamgar Gurevich (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_7 Harmonic Analysis on $GL_n$ over finite fields] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 14<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~thyang/ Tonghai Yang (UW-Madison)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_14 The Lambda invariant and its CM values]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 21<br />
| bgcolor="#F0B0B0" align="center" | No Seminar<br />
| bgcolor="#BCE2FE"|<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | Feb 28<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.columbia.edu/~brianrl/ Brian Lawrence (the University of Chicago)] <br />
| bgcolor="#BCE2FE"|[https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#Feb_28 Diophantine problems and a p-adic period map.] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 7<br />
| bgcolor="#F0B0B0" align="center" |[https://sites.google.com/view/masoudzargar/ Masoud Zargar (Regensburg)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_7 Sections of quadrics over the affine line] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 14<br />
| bgcolor="#F0B0B0" align="center" | [http://www.its.caltech.edu/~mantovan/ Elena Mantovan (Caltech)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_14 p-adic automorphic forms, differential operators and Galois representations]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 21<br />
| bgcolor="#F0B0B0" align="center" | Spring Break<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | March 28<br />
| bgcolor="#F0B0B0" align="center" | [http://web.math.ucsb.edu/~agboola/ Adebisi Agboola (UCSB)] <br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#March_28 Relative K-groups and rings of integers]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 4<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.tamu.edu/~wltsai/ Wei-Lun Tsai (Texas A&M University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_4 Hecke L-functions and $\ell$ torsion in class groups]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 11<br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~tmcadam/ Taylor McAdam (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Almost-prime times in horospherical flows]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 18 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.math.ucsd.edu/~ila/ Ila Varma (UCSD)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_11 Malle's Conjecture for octic $D_4$-fields.]<br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | ]<br />
| bgcolor="#BCE2FE"| [] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | []<br />
| bgcolor="#BCE2FE"| [] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | [https://math.rice.edu/~jb93/ Jen Berg (Rice University)]<br />
| bgcolor="#BCE2FE"| [https://www.math.wisc.edu/wiki/index.php/NTS_ABSTRACTSpring2019#April_25 Rational points on conic bundles over elliptic curves with positive rank] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | April 25<br />
| bgcolor="#F0B0B0" align="center" | []<br />
| bgcolor="#BCE2FE"| [] <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 2<br />
| bgcolor="#F0B0B0" align="center" | [https://www.math.wisc.edu/~mmwood/ Melanie Wood (UW-Madison)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
| bgcolor="#E0E0E0" align="center" | May 9 <br />
| bgcolor="#F0B0B0" align="center" | [http://www.mathcs.emory.edu/~dzb/ David Zureick-Brown (Emory College of Arts and Sciences)]<br />
| bgcolor="#BCE2FE"| <br />
|- <br />
|}<br />
</center><br />
<br />
<br><br />
<br />
*to be confirmed<br />
<br />
= Organizer contact information =<br />
<br />
[http://www.math.wisc.edu/~ntalebiz/ Naser Talebizadeh Sardari]<br />
<br />
[http://www.math.wisc.edu/~shusterman/ Mark Shusterman]<br />
<br />
[http://www.math.wisc.edu/~ruixiang/ Ruixiang Zhang]<br />
----<br />
Return to the [[Algebra|Algebra Group Page]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Reading_Seminar_2018-19&diff=17347Reading Seminar 2018-192019-04-18T22:27:15Z<p>Rdavis: </p>
<hr />
<div>==Overview==<br />
My (Daniel's) experience has been that reading seminars have diminishing returns: they run out of steam after about 8 lectures on a certain book, as everyone starts falling behind, etc. I was thinking aim broader (rather than deeper), covering 3 books, but with fewer lectures. My idea is to partly cover: Beauville's "Complex Algebraic Surfaces"; Atiyah's "K-theory" (1989 edition); and Harris and Morrison's "Moduli of Curves". We would do about 6-8 lectures on each. This allows us to reboot every two months, which I hope will be mentally refreshing and will allow people who have lost the thread of the book to rejoin. Anyways, it's an experiment!<br />
<br />
Some notes:<br />
<ul><br />
<li>Here is lecture notes from Ravi Vakil on Complex Algebraic Surfaces "http://math.stanford.edu/~vakil/02-245/index.html"<br />
<li> Each book will have a co-organizer: Wanlin Li for Beauville's book; Michael Brown for Atiyah's book; and Rachel Davis for Harris and Morrison's book. Thanks!</li><br />
<li>I left some "Makeup" dates in the schedule with the idea that we would most likely take a week off on those dates. But if we need to miss another date (because of a conflict with a special colloquium or some other event), then we can use those as makeup slots.</li><br />
</ul><br />
<br />
We are experimenting with lots of new formats in this year's seminar. If you aren't happy with how the reading seminar is going, please let one of the organizers (Daniel, Wanlin, Michael, or Rachel) know and we will do our best to get things back on a helpful track.<br />
<br />
==Time and Location==<br />
Talks will be on Fridays from 11:00-11:45 in B329. This semester, Daniel is planning to keep a VERY HARD watch on the clock.<br />
<br />
== Talk Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | sections<br />
<br />
|-<br />
|September 7<br />
|Wanlin Li<br />
|Beauville I<br />
|-<br />
|September 14<br />
|Rachel Davis<br />
|Beauville II<br />
|-<br />
|September 21<br />
|Brandon Boggess<br />
|Beauville II and III<br />
|-<br />
|September 28<br />
|Mao Li<br />
|Beauville III<br />
|-<br />
|October 5<br />
|Wendy Cheng<br />
|Beauville IV<br />
|-<br />
|October 12<br />
|Soumya Sankar<br />
|Beauville V<br />
|-<br />
|October 19<br />
|David Wagner<br />
|Beauville V and VI<br />
|-<br />
|October 26<br />
|Dan Corey<br />
|Beauville VII and VIII<br />
|-<br />
|November 2<br />
|No Meeting<br />
|Break<br />
|-<br />
|November 9<br />
|Michael Brown<br />
|Atiyah 1 (Overview of goals of the seminar, Section 2.1) <br />
|-<br />
|November 16<br />
|Asvin Gothandaraman<br />
|Atiyah 2 (Section 2.2)<br />
|-<br />
|November 23<br />
|NO MEETING<br />
|Thanksgiving<br />
|-<br />
|November 30<br />
|NO MEETING<br />
|<br />
|-<br />
|SEMESETER BREAK<br />
|No meetings<br />
|<br />
|-<br />
|January 25<br />
|Daniel Erman<br />
|Atiyah 3 (Section 2.5: Examples)<br />
|-<br />
|February 1<br />
|Rachel Davis<br />
|Atiyah 4 (Section 2.3: Bott periodicity)<br />
|-<br />
|February 8<br />
|Michael Brown<br />
|Atiyah 5 (Thom isomorphism)<br />
|-<br />
|February 15<br />
|Mao Li<br />
|Algebraic K theory, Localization theorem and flag variety.<br />
|-<br />
|February 22<br />
|No Meeting<br />
|-<br />
|March 1<br />
|No Meeting<br />
|-<br />
|March 8<br />
| Juliette Bruce<br />
|Moduli 1<br />
|-<br />
|March 15<br />
|Niudun Wang<br />
|Moduli 2<br />
|-<br />
|March 22<br />
|NO MEETING<br />
|Spring recess<br />
|-<br />
|March 29<br />
|Rachel Davis<br />
|Moduli 3<br />
|-<br />
|April 5<br />
|NO MEETING <br />
|There is an algebraic geometry seminar talk at this time (and another algebraic geometry seminar at the usual time). [https://www.math.wisc.edu/wiki/index.php/Algebra_and_Algebraic_Geometry_Seminar_Spring_2019 Algebra and algebraic geometry seminar]<br />
|-<br />
|April 12<br />
|NO MEETING<br />
|<br />
|-<br />
|April 19<br />
|NO MEETING!<br />
|<br />
|-<br />
|}<br />
<br />
==How to plan your talk==<br />
One key to giving good talks in a reading seminar is to know how to refocus the material that you read. Instead of going through the chapter lemma by lemma, you should ask: What is the main idea in this section? It could be a theorem, a definition, or even an example. But after reading the section, decide what the most important idea is and be sure to highlight early on.<br />
<br />
You will probably need to skip the proofs--and even the statements--of many of the lemmas and other results in the chapter. This is a good thing! The reason someone attends a talk, as opposed to just reading the material on their own, is because they want to see the material from the perspective of someone who has thought it about carefully.<br />
<br />
Also, make sure to give clear examples.<br />
<br />
<br />
==Feedback on talks==<br />
One of the goals for this semester is to help the speakers learn to give better talks. Here is our plan:<br />
<br />
<li> Feedback session: This is like a streamlined version of what creative writing workshops do. Every week, we reserve 15 minutes (12:35-12:50) for the entire audience to critique that week’s speaker. Comments will be friendly and constructive. A key rule is that the speaker is not allowed to speak until the last 5 minutes.</li><br />
<br />
<li> Partner: We assign a “partner” each week (usually the previous week's speaker). The partner will meet for 20-30 minutes with the speaker in advance to:<br />
<ol> Discuss a plan for the talk. Here the speaker can outline what they see as the main ideas, and the partner can share any wisdom gleaned from their experience the previous week. </ol><br />
<ol> Ask the speaker if there are any particular things that the speaker would like feedback on (e.g. pacing, boardwork, clarity of voice, etc.). </ol><br />
The partner would also take notes during the feedback session, to give the speaker a record of the conversation.<br />
</li><br />
<br />
This is very much an experiment, and while it might be intimidating at first, I actually think it could really help everyone (the speakers and the audience members too).</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Reading_Seminar_2018-19&diff=17271Reading Seminar 2018-192019-04-02T13:20:16Z<p>Rdavis: </p>
<hr />
<div>==Overview==<br />
My (Daniel's) experience has been that reading seminars have diminishing returns: they run out of steam after about 8 lectures on a certain book, as everyone starts falling behind, etc. I was thinking aim broader (rather than deeper), covering 3 books, but with fewer lectures. My idea is to partly cover: Beauville's "Complex Algebraic Surfaces"; Atiyah's "K-theory" (1989 edition); and Harris and Morrison's "Moduli of Curves". We would do about 6-8 lectures on each. This allows us to reboot every two months, which I hope will be mentally refreshing and will allow people who have lost the thread of the book to rejoin. Anyways, it's an experiment!<br />
<br />
Some notes:<br />
<ul><br />
<li>Here is lecture notes from Ravi Vakil on Complex Algebraic Surfaces "http://math.stanford.edu/~vakil/02-245/index.html"<br />
<li> Each book will have a co-organizer: Wanlin Li for Beauville's book; Michael Brown for Atiyah's book; and Rachel Davis for Harris and Morrison's book. Thanks!</li><br />
<li>I left some "Makeup" dates in the schedule with the idea that we would most likely take a week off on those dates. But if we need to miss another date (because of a conflict with a special colloquium or some other event), then we can use those as makeup slots.</li><br />
</ul><br />
<br />
We are experimenting with lots of new formats in this year's seminar. If you aren't happy with how the reading seminar is going, please let one of the organizers (Daniel, Wanlin, Michael, or Rachel) know and we will do our best to get things back on a helpful track.<br />
<br />
==Time and Location==<br />
Talks will be on Fridays from 11:00-11:45 in B329. This semester, Daniel is planning to keep a VERY HARD watch on the clock.<br />
<br />
== Talk Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | sections<br />
<br />
|-<br />
|September 7<br />
|Wanlin Li<br />
|Beauville I<br />
|-<br />
|September 14<br />
|Rachel Davis<br />
|Beauville II<br />
|-<br />
|September 21<br />
|Brandon Boggess<br />
|Beauville II and III<br />
|-<br />
|September 28<br />
|Mao Li<br />
|Beauville III<br />
|-<br />
|October 5<br />
|Wendy Cheng<br />
|Beauville IV<br />
|-<br />
|October 12<br />
|Soumya Sankar<br />
|Beauville V<br />
|-<br />
|October 19<br />
|David Wagner<br />
|Beauville V and VI<br />
|-<br />
|October 26<br />
|Dan Corey<br />
|Beauville VII and VIII<br />
|-<br />
|November 2<br />
|No Meeting<br />
|Break<br />
|-<br />
|November 9<br />
|Michael Brown<br />
|Atiyah 1 (Overview of goals of the seminar, Section 2.1) <br />
|-<br />
|November 16<br />
|Asvin Gothandaraman<br />
|Atiyah 2 (Section 2.2)<br />
|-<br />
|November 23<br />
|NO MEETING<br />
|Thanksgiving<br />
|-<br />
|November 30<br />
|NO MEETING<br />
|<br />
|-<br />
|SEMESETER BREAK<br />
|No meetings<br />
|<br />
|-<br />
|January 25<br />
|Daniel Erman<br />
|Atiyah 3 (Section 2.5: Examples)<br />
|-<br />
|February 1<br />
|Rachel Davis<br />
|Atiyah 4 (Section 2.3: Bott periodicity)<br />
|-<br />
|February 8<br />
|Michael Brown<br />
|Atiyah 5 (Thom isomorphism)<br />
|-<br />
|February 15<br />
|Mao Li<br />
|Algebraic K theory, Localization theorem and flag variety.<br />
|-<br />
|February 22<br />
|No Meeting<br />
|-<br />
|March 1<br />
|No Meeting<br />
|-<br />
|March 8<br />
| Juliette Bruce<br />
|Moduli 1<br />
|-<br />
|March 15<br />
|Niudun Wang<br />
|Moduli 2<br />
|-<br />
|March 22<br />
|NO MEETING<br />
|Spring recess<br />
|-<br />
|March 29<br />
|Rachel Davis<br />
|Moduli 3<br />
|-<br />
|April 5<br />
|NO MEETING <br />
|There is an algebraic geometry seminar talk at this time (and another algebraic geometry seminar at the usual time). [https://www.math.wisc.edu/wiki/index.php/Algebra_and_Algebraic_Geometry_Seminar_Spring_2019 Algebra and algebraic geometry seminar]<br />
|-<br />
|April 12<br />
|NO MEETING<br />
|<br />
|-<br />
|April 19<br />
|Daniel Erman<br />
|Deformation theory of curves<br />
|-<br />
|}<br />
<br />
==How to plan your talk==<br />
One key to giving good talks in a reading seminar is to know how to refocus the material that you read. Instead of going through the chapter lemma by lemma, you should ask: What is the main idea in this section? It could be a theorem, a definition, or even an example. But after reading the section, decide what the most important idea is and be sure to highlight early on.<br />
<br />
You will probably need to skip the proofs--and even the statements--of many of the lemmas and other results in the chapter. This is a good thing! The reason someone attends a talk, as opposed to just reading the material on their own, is because they want to see the material from the perspective of someone who has thought it about carefully.<br />
<br />
Also, make sure to give clear examples.<br />
<br />
<br />
==Feedback on talks==<br />
One of the goals for this semester is to help the speakers learn to give better talks. Here is our plan:<br />
<br />
<li> Feedback session: This is like a streamlined version of what creative writing workshops do. Every week, we reserve 15 minutes (12:35-12:50) for the entire audience to critique that week’s speaker. Comments will be friendly and constructive. A key rule is that the speaker is not allowed to speak until the last 5 minutes.</li><br />
<br />
<li> Partner: We assign a “partner” each week (usually the previous week's speaker). The partner will meet for 20-30 minutes with the speaker in advance to:<br />
<ol> Discuss a plan for the talk. Here the speaker can outline what they see as the main ideas, and the partner can share any wisdom gleaned from their experience the previous week. </ol><br />
<ol> Ask the speaker if there are any particular things that the speaker would like feedback on (e.g. pacing, boardwork, clarity of voice, etc.). </ol><br />
The partner would also take notes during the feedback session, to give the speaker a record of the conversation.<br />
</li><br />
<br />
This is very much an experiment, and while it might be intimidating at first, I actually think it could really help everyone (the speakers and the audience members too).</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Reading_Seminar_2018-19&diff=17270Reading Seminar 2018-192019-04-02T13:19:32Z<p>Rdavis: </p>
<hr />
<div>==Overview==<br />
My (Daniel's) experience has been that reading seminars have diminishing returns: they run out of steam after about 8 lectures on a certain book, as everyone starts falling behind, etc. I was thinking aim broader (rather than deeper), covering 3 books, but with fewer lectures. My idea is to partly cover: Beauville's "Complex Algebraic Surfaces"; Atiyah's "K-theory" (1989 edition); and Harris and Morrison's "Moduli of Curves". We would do about 6-8 lectures on each. This allows us to reboot every two months, which I hope will be mentally refreshing and will allow people who have lost the thread of the book to rejoin. Anyways, it's an experiment!<br />
<br />
Some notes:<br />
<ul><br />
<li>Here is lecture notes from Ravi Vakil on Complex Algebraic Surfaces "http://math.stanford.edu/~vakil/02-245/index.html"<br />
<li> Each book will have a co-organizer: Wanlin Li for Beauville's book; Michael Brown for Atiyah's book; and Rachel Davis for Harris and Morrison's book. Thanks!</li><br />
<li>I left some "Makeup" dates in the schedule with the idea that we would most likely take a week off on those dates. But if we need to miss another date (because of a conflict with a special colloquium or some other event), then we can use those as makeup slots.</li><br />
</ul><br />
<br />
We are experimenting with lots of new formats in this year's seminar. If you aren't happy with how the reading seminar is going, please let one of the organizers (Daniel, Wanlin, Michael, or Rachel) know and we will do our best to get things back on a helpful track.<br />
<br />
==Time and Location==<br />
Talks will be on Fridays from 11:00-11:45 in B329. This semester, Daniel is planning to keep a VERY HARD watch on the clock.<br />
<br />
== Talk Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | sections<br />
<br />
|-<br />
|September 7<br />
|Wanlin Li<br />
|Beauville I<br />
|-<br />
|September 14<br />
|Rachel Davis<br />
|Beauville II<br />
|-<br />
|September 21<br />
|Brandon Boggess<br />
|Beauville II and III<br />
|-<br />
|September 28<br />
|Mao Li<br />
|Beauville III<br />
|-<br />
|October 5<br />
|Wendy Cheng<br />
|Beauville IV<br />
|-<br />
|October 12<br />
|Soumya Sankar<br />
|Beauville V<br />
|-<br />
|October 19<br />
|David Wagner<br />
|Beauville V and VI<br />
|-<br />
|October 26<br />
|Dan Corey<br />
|Beauville VII and VIII<br />
|-<br />
|November 2<br />
|No Meeting<br />
|Break<br />
|-<br />
|November 9<br />
|Michael Brown<br />
|Atiyah 1 (Overview of goals of the seminar, Section 2.1) <br />
|-<br />
|November 16<br />
|Asvin Gothandaraman<br />
|Atiyah 2 (Section 2.2)<br />
|-<br />
|November 23<br />
|NO MEETING<br />
|Thanksgiving<br />
|-<br />
|November 30<br />
|NO MEETING<br />
|<br />
|-<br />
|SEMESETER BREAK<br />
|No meetings<br />
|<br />
|-<br />
|January 25<br />
|Daniel Erman<br />
|Atiyah 3 (Section 2.5: Examples)<br />
|-<br />
|February 1<br />
|Rachel Davis<br />
|Atiyah 4 (Section 2.3: Bott periodicity)<br />
|-<br />
|February 8<br />
|Michael Brown<br />
|Atiyah 5 (Thom isomorphism)<br />
|-<br />
|February 15<br />
|Mao Li<br />
|Algebraic K theory, Localization theorem and flag variety.<br />
|-<br />
|February 22<br />
|No Meeting<br />
|-<br />
|March 1<br />
|No Meeting<br />
|-<br />
|March 8<br />
| Juliette Bruce<br />
|Moduli 1<br />
|-<br />
|March 15<br />
|Niudun Wang<br />
|Moduli 2<br />
|-<br />
|March 22<br />
|NO MEETING<br />
|Spring recess<br />
|-<br />
|March 29<br />
|Rachel Davis<br />
|Moduli 3<br />
|-<br />
|April 5<br />
|NO MEETING <br />
|There is an algebraic geometry seminar talk at this time (and another algebraic geometry seminar at the usual time). [https://www.math.wisc.edu/wiki/index.php/Algebra_and_Algebraic_Geometry_Seminar_Spring_2019/ Algebra and algebraic geometry seminar]<br />
|-<br />
|April 12<br />
|NO MEETING<br />
|<br />
|-<br />
|April 19<br />
|Daniel Erman<br />
|Deformation theory of curves<br />
|-<br />
|}<br />
<br />
==How to plan your talk==<br />
One key to giving good talks in a reading seminar is to know how to refocus the material that you read. Instead of going through the chapter lemma by lemma, you should ask: What is the main idea in this section? It could be a theorem, a definition, or even an example. But after reading the section, decide what the most important idea is and be sure to highlight early on.<br />
<br />
You will probably need to skip the proofs--and even the statements--of many of the lemmas and other results in the chapter. This is a good thing! The reason someone attends a talk, as opposed to just reading the material on their own, is because they want to see the material from the perspective of someone who has thought it about carefully.<br />
<br />
Also, make sure to give clear examples.<br />
<br />
<br />
==Feedback on talks==<br />
One of the goals for this semester is to help the speakers learn to give better talks. Here is our plan:<br />
<br />
<li> Feedback session: This is like a streamlined version of what creative writing workshops do. Every week, we reserve 15 minutes (12:35-12:50) for the entire audience to critique that week’s speaker. Comments will be friendly and constructive. A key rule is that the speaker is not allowed to speak until the last 5 minutes.</li><br />
<br />
<li> Partner: We assign a “partner” each week (usually the previous week's speaker). The partner will meet for 20-30 minutes with the speaker in advance to:<br />
<ol> Discuss a plan for the talk. Here the speaker can outline what they see as the main ideas, and the partner can share any wisdom gleaned from their experience the previous week. </ol><br />
<ol> Ask the speaker if there are any particular things that the speaker would like feedback on (e.g. pacing, boardwork, clarity of voice, etc.). </ol><br />
The partner would also take notes during the feedback session, to give the speaker a record of the conversation.<br />
</li><br />
<br />
This is very much an experiment, and while it might be intimidating at first, I actually think it could really help everyone (the speakers and the audience members too).</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Reading_Seminar_2018-19&diff=17269Reading Seminar 2018-192019-04-02T13:16:22Z<p>Rdavis: </p>
<hr />
<div>==Overview==<br />
My (Daniel's) experience has been that reading seminars have diminishing returns: they run out of steam after about 8 lectures on a certain book, as everyone starts falling behind, etc. I was thinking aim broader (rather than deeper), covering 3 books, but with fewer lectures. My idea is to partly cover: Beauville's "Complex Algebraic Surfaces"; Atiyah's "K-theory" (1989 edition); and Harris and Morrison's "Moduli of Curves". We would do about 6-8 lectures on each. This allows us to reboot every two months, which I hope will be mentally refreshing and will allow people who have lost the thread of the book to rejoin. Anyways, it's an experiment!<br />
<br />
Some notes:<br />
<ul><br />
<li>Here is lecture notes from Ravi Vakil on Complex Algebraic Surfaces "http://math.stanford.edu/~vakil/02-245/index.html"<br />
<li> Each book will have a co-organizer: Wanlin Li for Beauville's book; Michael Brown for Atiyah's book; and Rachel Davis for Harris and Morrison's book. Thanks!</li><br />
<li>I left some "Makeup" dates in the schedule with the idea that we would most likely take a week off on those dates. But if we need to miss another date (because of a conflict with a special colloquium or some other event), then we can use those as makeup slots.</li><br />
</ul><br />
<br />
We are experimenting with lots of new formats in this year's seminar. If you aren't happy with how the reading seminar is going, please let one of the organizers (Daniel, Wanlin, Michael, or Rachel) know and we will do our best to get things back on a helpful track.<br />
<br />
==Time and Location==<br />
Talks will be on Fridays from 11:00-11:45 in B329. This semester, Daniel is planning to keep a VERY HARD watch on the clock.<br />
<br />
== Talk Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | sections<br />
<br />
|-<br />
|September 7<br />
|Wanlin Li<br />
|Beauville I<br />
|-<br />
|September 14<br />
|Rachel Davis<br />
|Beauville II<br />
|-<br />
|September 21<br />
|Brandon Boggess<br />
|Beauville II and III<br />
|-<br />
|September 28<br />
|Mao Li<br />
|Beauville III<br />
|-<br />
|October 5<br />
|Wendy Cheng<br />
|Beauville IV<br />
|-<br />
|October 12<br />
|Soumya Sankar<br />
|Beauville V<br />
|-<br />
|October 19<br />
|David Wagner<br />
|Beauville V and VI<br />
|-<br />
|October 26<br />
|Dan Corey<br />
|Beauville VII and VIII<br />
|-<br />
|November 2<br />
|No Meeting<br />
|Break<br />
|-<br />
|November 9<br />
|Michael Brown<br />
|Atiyah 1 (Overview of goals of the seminar, Section 2.1) <br />
|-<br />
|November 16<br />
|Asvin Gothandaraman<br />
|Atiyah 2 (Section 2.2)<br />
|-<br />
|November 23<br />
|NO MEETING<br />
|Thanksgiving<br />
|-<br />
|November 30<br />
|NO MEETING<br />
|<br />
|-<br />
|SEMESETER BREAK<br />
|No meetings<br />
|<br />
|-<br />
|January 25<br />
|Daniel Erman<br />
|Atiyah 3 (Section 2.5: Examples)<br />
|-<br />
|February 1<br />
|Rachel Davis<br />
|Atiyah 4 (Section 2.3: Bott periodicity)<br />
|-<br />
|February 8<br />
|Michael Brown<br />
|Atiyah 5 (Thom isomorphism)<br />
|-<br />
|February 15<br />
|Mao Li<br />
|Algebraic K theory, Localization theorem and flag variety.<br />
|-<br />
|February 22<br />
|No Meeting<br />
|-<br />
|March 1<br />
|No Meeting<br />
|-<br />
|March 8<br />
| Juliette Bruce<br />
|Moduli 1<br />
|-<br />
|March 15<br />
|Niudun Wang<br />
|Moduli 2<br />
|-<br />
|March 22<br />
|NO MEETING<br />
|Spring recess<br />
|-<br />
|March 29<br />
|Rachel Davis<br />
|Moduli 3<br />
|-<br />
|April 5<br />
|NO MEETING <br />
|There is an algebraic geometry seminar talk at this time (and another algebraic geometry seminar at the usual time). [http://www.math.wisc.edu/wiki/index.php/Algebra_and_Algebraic_Geometry_Seminar_Spring_2019/ Algebra and algebraic geometry seminar]<br />
|-<br />
|April 12<br />
|NO MEETING<br />
|<br />
|-<br />
|April 19<br />
|Daniel Erman<br />
|Deformation theory of curves<br />
|-<br />
|}<br />
<br />
==How to plan your talk==<br />
One key to giving good talks in a reading seminar is to know how to refocus the material that you read. Instead of going through the chapter lemma by lemma, you should ask: What is the main idea in this section? It could be a theorem, a definition, or even an example. But after reading the section, decide what the most important idea is and be sure to highlight early on.<br />
<br />
You will probably need to skip the proofs--and even the statements--of many of the lemmas and other results in the chapter. This is a good thing! The reason someone attends a talk, as opposed to just reading the material on their own, is because they want to see the material from the perspective of someone who has thought it about carefully.<br />
<br />
Also, make sure to give clear examples.<br />
<br />
<br />
==Feedback on talks==<br />
One of the goals for this semester is to help the speakers learn to give better talks. Here is our plan:<br />
<br />
<li> Feedback session: This is like a streamlined version of what creative writing workshops do. Every week, we reserve 15 minutes (12:35-12:50) for the entire audience to critique that week’s speaker. Comments will be friendly and constructive. A key rule is that the speaker is not allowed to speak until the last 5 minutes.</li><br />
<br />
<li> Partner: We assign a “partner” each week (usually the previous week's speaker). The partner will meet for 20-30 minutes with the speaker in advance to:<br />
<ol> Discuss a plan for the talk. Here the speaker can outline what they see as the main ideas, and the partner can share any wisdom gleaned from their experience the previous week. </ol><br />
<ol> Ask the speaker if there are any particular things that the speaker would like feedback on (e.g. pacing, boardwork, clarity of voice, etc.). </ol><br />
The partner would also take notes during the feedback session, to give the speaker a record of the conversation.<br />
</li><br />
<br />
This is very much an experiment, and while it might be intimidating at first, I actually think it could really help everyone (the speakers and the audience members too).</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Reading_Seminar_2018-19&diff=17268Reading Seminar 2018-192019-04-02T13:15:25Z<p>Rdavis: </p>
<hr />
<div>==Overview==<br />
My (Daniel's) experience has been that reading seminars have diminishing returns: they run out of steam after about 8 lectures on a certain book, as everyone starts falling behind, etc. I was thinking aim broader (rather than deeper), covering 3 books, but with fewer lectures. My idea is to partly cover: Beauville's "Complex Algebraic Surfaces"; Atiyah's "K-theory" (1989 edition); and Harris and Morrison's "Moduli of Curves". We would do about 6-8 lectures on each. This allows us to reboot every two months, which I hope will be mentally refreshing and will allow people who have lost the thread of the book to rejoin. Anyways, it's an experiment!<br />
<br />
Some notes:<br />
<ul><br />
<li>Here is lecture notes from Ravi Vakil on Complex Algebraic Surfaces "http://math.stanford.edu/~vakil/02-245/index.html"<br />
<li> Each book will have a co-organizer: Wanlin Li for Beauville's book; Michael Brown for Atiyah's book; and Rachel Davis for Harris and Morrison's book. Thanks!</li><br />
<li>I left some "Makeup" dates in the schedule with the idea that we would most likely take a week off on those dates. But if we need to miss another date (because of a conflict with a special colloquium or some other event), then we can use those as makeup slots.</li><br />
</ul><br />
<br />
We are experimenting with lots of new formats in this year's seminar. If you aren't happy with how the reading seminar is going, please let one of the organizers (Daniel, Wanlin, Michael, or Rachel) know and we will do our best to get things back on a helpful track.<br />
<br />
==Time and Location==<br />
Talks will be on Fridays from 11:00-11:45 in B329. This semester, Daniel is planning to keep a VERY HARD watch on the clock.<br />
<br />
== Talk Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | sections<br />
<br />
|-<br />
|September 7<br />
|Wanlin Li<br />
|Beauville I<br />
|-<br />
|September 14<br />
|Rachel Davis<br />
|Beauville II<br />
|-<br />
|September 21<br />
|Brandon Boggess<br />
|Beauville II and III<br />
|-<br />
|September 28<br />
|Mao Li<br />
|Beauville III<br />
|-<br />
|October 5<br />
|Wendy Cheng<br />
|Beauville IV<br />
|-<br />
|October 12<br />
|Soumya Sankar<br />
|Beauville V<br />
|-<br />
|October 19<br />
|David Wagner<br />
|Beauville V and VI<br />
|-<br />
|October 26<br />
|Dan Corey<br />
|Beauville VII and VIII<br />
|-<br />
|November 2<br />
|No Meeting<br />
|Break<br />
|-<br />
|November 9<br />
|Michael Brown<br />
|Atiyah 1 (Overview of goals of the seminar, Section 2.1) <br />
|-<br />
|November 16<br />
|Asvin Gothandaraman<br />
|Atiyah 2 (Section 2.2)<br />
|-<br />
|November 23<br />
|NO MEETING<br />
|Thanksgiving<br />
|-<br />
|November 30<br />
|NO MEETING<br />
|<br />
|-<br />
|SEMESETER BREAK<br />
|No meetings<br />
|<br />
|-<br />
|January 25<br />
|Daniel Erman<br />
|Atiyah 3 (Section 2.5: Examples)<br />
|-<br />
|February 1<br />
|Rachel Davis<br />
|Atiyah 4 (Section 2.3: Bott periodicity)<br />
|-<br />
|February 8<br />
|Michael Brown<br />
|Atiyah 5 (Thom isomorphism)<br />
|-<br />
|February 15<br />
|Mao Li<br />
|Algebraic K theory, Localization theorem and flag variety.<br />
|-<br />
|February 22<br />
|No Meeting<br />
|-<br />
|March 1<br />
|No Meeting<br />
|-<br />
|March 8<br />
| Juliette Bruce<br />
|Moduli 1<br />
|-<br />
|March 15<br />
|Niudun Wang<br />
|Moduli 2<br />
|-<br />
|March 22<br />
|NO MEETING<br />
|Spring recess<br />
|-<br />
|March 29<br />
|Rachel Davis<br />
|Moduli 3<br />
|-<br />
|April 5<br />
|NO MEETING <br />
|There is an algebraic geometry seminar talk at this time (and another algebraic geometry seminar at the usual time). [https://www.math.wisc.edu/wiki/index.php/Algebra_and_Algebraic_Geometry_Seminar_Spring_2019/ Algebra and algebraic geometry seminar]<br />
|-<br />
|April 12<br />
|NO MEETING<br />
|<br />
|-<br />
|April 19<br />
|Daniel Erman<br />
|Deformation theory of curves<br />
|-<br />
|}<br />
<br />
==How to plan your talk==<br />
One key to giving good talks in a reading seminar is to know how to refocus the material that you read. Instead of going through the chapter lemma by lemma, you should ask: What is the main idea in this section? It could be a theorem, a definition, or even an example. But after reading the section, decide what the most important idea is and be sure to highlight early on.<br />
<br />
You will probably need to skip the proofs--and even the statements--of many of the lemmas and other results in the chapter. This is a good thing! The reason someone attends a talk, as opposed to just reading the material on their own, is because they want to see the material from the perspective of someone who has thought it about carefully.<br />
<br />
Also, make sure to give clear examples.<br />
<br />
<br />
==Feedback on talks==<br />
One of the goals for this semester is to help the speakers learn to give better talks. Here is our plan:<br />
<br />
<li> Feedback session: This is like a streamlined version of what creative writing workshops do. Every week, we reserve 15 minutes (12:35-12:50) for the entire audience to critique that week’s speaker. Comments will be friendly and constructive. A key rule is that the speaker is not allowed to speak until the last 5 minutes.</li><br />
<br />
<li> Partner: We assign a “partner” each week (usually the previous week's speaker). The partner will meet for 20-30 minutes with the speaker in advance to:<br />
<ol> Discuss a plan for the talk. Here the speaker can outline what they see as the main ideas, and the partner can share any wisdom gleaned from their experience the previous week. </ol><br />
<ol> Ask the speaker if there are any particular things that the speaker would like feedback on (e.g. pacing, boardwork, clarity of voice, etc.). </ol><br />
The partner would also take notes during the feedback session, to give the speaker a record of the conversation.<br />
</li><br />
<br />
This is very much an experiment, and while it might be intimidating at first, I actually think it could really help everyone (the speakers and the audience members too).</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Reading_Seminar_2018-19&diff=17267Reading Seminar 2018-192019-04-02T13:13:27Z<p>Rdavis: </p>
<hr />
<div>==Overview==<br />
My (Daniel's) experience has been that reading seminars have diminishing returns: they run out of steam after about 8 lectures on a certain book, as everyone starts falling behind, etc. I was thinking aim broader (rather than deeper), covering 3 books, but with fewer lectures. My idea is to partly cover: Beauville's "Complex Algebraic Surfaces"; Atiyah's "K-theory" (1989 edition); and Harris and Morrison's "Moduli of Curves". We would do about 6-8 lectures on each. This allows us to reboot every two months, which I hope will be mentally refreshing and will allow people who have lost the thread of the book to rejoin. Anyways, it's an experiment!<br />
<br />
Some notes:<br />
<ul><br />
<li>Here is lecture notes from Ravi Vakil on Complex Algebraic Surfaces "http://math.stanford.edu/~vakil/02-245/index.html"<br />
<li> Each book will have a co-organizer: Wanlin Li for Beauville's book; Michael Brown for Atiyah's book; and Rachel Davis for Harris and Morrison's book. Thanks!</li><br />
<li>I left some "Makeup" dates in the schedule with the idea that we would most likely take a week off on those dates. But if we need to miss another date (because of a conflict with a special colloquium or some other event), then we can use those as makeup slots.</li><br />
</ul><br />
<br />
We are experimenting with lots of new formats in this year's seminar. If you aren't happy with how the reading seminar is going, please let one of the organizers (Daniel, Wanlin, Michael, or Rachel) know and we will do our best to get things back on a helpful track.<br />
<br />
==Time and Location==<br />
Talks will be on Fridays from 11:00-11:45 in B329. This semester, Daniel is planning to keep a VERY HARD watch on the clock.<br />
<br />
== Talk Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | sections<br />
<br />
|-<br />
|September 7<br />
|Wanlin Li<br />
|Beauville I<br />
|-<br />
|September 14<br />
|Rachel Davis<br />
|Beauville II<br />
|-<br />
|September 21<br />
|Brandon Boggess<br />
|Beauville II and III<br />
|-<br />
|September 28<br />
|Mao Li<br />
|Beauville III<br />
|-<br />
|October 5<br />
|Wendy Cheng<br />
|Beauville IV<br />
|-<br />
|October 12<br />
|Soumya Sankar<br />
|Beauville V<br />
|-<br />
|October 19<br />
|David Wagner<br />
|Beauville V and VI<br />
|-<br />
|October 26<br />
|Dan Corey<br />
|Beauville VII and VIII<br />
|-<br />
|November 2<br />
|No Meeting<br />
|Break<br />
|-<br />
|November 9<br />
|Michael Brown<br />
|Atiyah 1 (Overview of goals of the seminar, Section 2.1) <br />
|-<br />
|November 16<br />
|Asvin Gothandaraman<br />
|Atiyah 2 (Section 2.2)<br />
|-<br />
|November 23<br />
|NO MEETING<br />
|Thanksgiving<br />
|-<br />
|November 30<br />
|NO MEETING<br />
|<br />
|-<br />
|SEMESETER BREAK<br />
|No meetings<br />
|<br />
|-<br />
|January 25<br />
|Daniel Erman<br />
|Atiyah 3 (Section 2.5: Examples)<br />
|-<br />
|February 1<br />
|Rachel Davis<br />
|Atiyah 4 (Section 2.3: Bott periodicity)<br />
|-<br />
|February 8<br />
|Michael Brown<br />
|Atiyah 5 (Thom isomorphism)<br />
|-<br />
|February 15<br />
|Mao Li<br />
|Algebraic K theory, Localization theorem and flag variety.<br />
|-<br />
|February 22<br />
|No Meeting<br />
|-<br />
|March 1<br />
|No Meeting<br />
|-<br />
|March 8<br />
| Juliette Bruce<br />
|Moduli 1<br />
|-<br />
|March 15<br />
|Niudun Wang<br />
|Moduli 2<br />
|-<br />
|March 22<br />
|NO MEETING<br />
|Spring recess<br />
|-<br />
|March 29<br />
|Rachel Davis<br />
|Moduli 3<br />
|-<br />
|April 5<br />
|NO MEETING <br />
|There is an algebraic geometry seminar talk at this time (and another algebraic geometry seminar at the usual time).<br />
|-<br />
|April 12<br />
|NO MEETING<br />
|<br />
|-<br />
|April 19<br />
|Daniel Erman<br />
|Deformation theory of curves<br />
|-<br />
|}<br />
<br />
==How to plan your talk==<br />
One key to giving good talks in a reading seminar is to know how to refocus the material that you read. Instead of going through the chapter lemma by lemma, you should ask: What is the main idea in this section? It could be a theorem, a definition, or even an example. But after reading the section, decide what the most important idea is and be sure to highlight early on.<br />
<br />
You will probably need to skip the proofs--and even the statements--of many of the lemmas and other results in the chapter. This is a good thing! The reason someone attends a talk, as opposed to just reading the material on their own, is because they want to see the material from the perspective of someone who has thought it about carefully.<br />
<br />
Also, make sure to give clear examples.<br />
<br />
<br />
==Feedback on talks==<br />
One of the goals for this semester is to help the speakers learn to give better talks. Here is our plan:<br />
<br />
<li> Feedback session: This is like a streamlined version of what creative writing workshops do. Every week, we reserve 15 minutes (12:35-12:50) for the entire audience to critique that week’s speaker. Comments will be friendly and constructive. A key rule is that the speaker is not allowed to speak until the last 5 minutes.</li><br />
<br />
<li> Partner: We assign a “partner” each week (usually the previous week's speaker). The partner will meet for 20-30 minutes with the speaker in advance to:<br />
<ol> Discuss a plan for the talk. Here the speaker can outline what they see as the main ideas, and the partner can share any wisdom gleaned from their experience the previous week. </ol><br />
<ol> Ask the speaker if there are any particular things that the speaker would like feedback on (e.g. pacing, boardwork, clarity of voice, etc.). </ol><br />
The partner would also take notes during the feedback session, to give the speaker a record of the conversation.<br />
</li><br />
<br />
This is very much an experiment, and while it might be intimidating at first, I actually think it could really help everyone (the speakers and the audience members too).</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Reading_Seminar_2018-19&diff=17123Reading Seminar 2018-192019-03-07T22:46:53Z<p>Rdavis: </p>
<hr />
<div>==Overview==<br />
My (Daniel's) experience has been that reading seminars have diminishing returns: they run out of steam after about 8 lectures on a certain book, as everyone starts falling behind, etc. I was thinking aim broader (rather than deeper), covering 3 books, but with fewer lectures. My idea is to partly cover: Beauville's "Complex Algebraic Surfaces"; Atiyah's "K-theory" (1989 edition); and Harris and Morrison's "Moduli of Curves". We would do about 6-8 lectures on each. This allows us to reboot every two months, which I hope will be mentally refreshing and will allow people who have lost the thread of the book to rejoin. Anyways, it's an experiment!<br />
<br />
Some notes:<br />
<ul><br />
<li>Here is lecture notes from Ravi Vakil on Complex Algebraic Surfaces "http://math.stanford.edu/~vakil/02-245/index.html"<br />
<li> Each book will have a co-organizer: Wanlin Li for Beauville's book; Michael Brown for Atiyah's book; and Rachel Davis for Harris and Morrison's book. Thanks!</li><br />
<li>I left some "Makeup" dates in the schedule with the idea that we would most likely take a week off on those dates. But if we need to miss another date (because of a conflict with a special colloquium or some other event), then we can use those as makeup slots.</li><br />
</ul><br />
<br />
We are experimenting with lots of new formats in this year's seminar. If you aren't happy with how the reading seminar is going, please let one of the organizers (Daniel, Wanlin, Michael, or Rachel) know and we will do our best to get things back on a helpful track.<br />
<br />
==Time and Location==<br />
Talks will be on Fridays from 11:00-11:45 in B329. This semester, Daniel is planning to keep a VERY HARD watch on the clock.<br />
<br />
== Talk Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | sections<br />
<br />
|-<br />
|September 7<br />
|Wanlin Li<br />
|Beauville I<br />
|-<br />
|September 14<br />
|Rachel Davis<br />
|Beauville II<br />
|-<br />
|September 21<br />
|Brandon Boggess<br />
|Beauville II and III<br />
|-<br />
|September 28<br />
|Mao Li<br />
|Beauville III<br />
|-<br />
|October 5<br />
|Wendy Cheng<br />
|Beauville IV<br />
|-<br />
|October 12<br />
|Soumya Sankar<br />
|Beauville V<br />
|-<br />
|October 19<br />
|David Wagner<br />
|Beauville V and VI<br />
|-<br />
|October 26<br />
|Dan Corey<br />
|Beauville VII and VIII<br />
|-<br />
|November 2<br />
|No Meeting<br />
|Break<br />
|-<br />
|November 9<br />
|Michael Brown<br />
|Atiyah 1 (Overview of goals of the seminar, Section 2.1) <br />
|-<br />
|November 16<br />
|Asvin Gothandaraman<br />
|Atiyah 2 (Section 2.2)<br />
|-<br />
|November 23<br />
|NO MEETING<br />
|Thanksgiving<br />
|-<br />
|November 30<br />
|NO MEETING<br />
|<br />
|-<br />
|SEMESETER BREAK<br />
|No meetings<br />
|<br />
|-<br />
|January 25<br />
|Daniel Erman<br />
|Atiyah 3 (Section 2.5: Examples)<br />
|-<br />
|February 1<br />
|Rachel Davis<br />
|Atiyah 4 (Section 2.3: Bott periodicity)<br />
|-<br />
|February 8<br />
|Michael Brown<br />
|Atiyah 5 (Thom isomorphism)<br />
|-<br />
|February 15<br />
|Mao Li<br />
|Algebraic K theory, Localization theorem and flag variety.<br />
|-<br />
|February 22<br />
|No Meeting<br />
|-<br />
|March 1<br />
|No Meeting<br />
|-<br />
|March 8<br />
| Juliette Bruce<br />
|Moduli 1<br />
|-<br />
|March 15<br />
|Niudun Wang<br />
|Moduli 2<br />
|-<br />
|March 22<br />
|NO MEETING<br />
|Spring recess<br />
|-<br />
|March 29<br />
|Rachel Davis<br />
|Moduli 3<br />
|-<br />
|April 5<br />
|Michael Brown<br />
|Moduli 4<br />
|-<br />
|April 12<br />
|Brandon Boggess<br />
|Moduli 5<br />
|-<br />
|April 19<br />
|??<br />
|Moduli 6<br />
|-<br />
|}<br />
<br />
==How to plan your talk==<br />
One key to giving good talks in a reading seminar is to know how to refocus the material that you read. Instead of going through the chapter lemma by lemma, you should ask: What is the main idea in this section? It could be a theorem, a definition, or even an example. But after reading the section, decide what the most important idea is and be sure to highlight early on.<br />
<br />
You will probably need to skip the proofs--and even the statements--of many of the lemmas and other results in the chapter. This is a good thing! The reason someone attends a talk, as opposed to just reading the material on their own, is because they want to see the material from the perspective of someone who has thought it about carefully.<br />
<br />
Also, make sure to give clear examples.<br />
<br />
<br />
==Feedback on talks==<br />
One of the goals for this semester is to help the speakers learn to give better talks. Here is our plan:<br />
<br />
<li> Feedback session: This is like a streamlined version of what creative writing workshops do. Every week, we reserve 15 minutes (12:35-12:50) for the entire audience to critique that week’s speaker. Comments will be friendly and constructive. A key rule is that the speaker is not allowed to speak until the last 5 minutes.</li><br />
<br />
<li> Partner: We assign a “partner” each week (usually the previous week's speaker). The partner will meet for 20-30 minutes with the speaker in advance to:<br />
<ol> Discuss a plan for the talk. Here the speaker can outline what they see as the main ideas, and the partner can share any wisdom gleaned from their experience the previous week. </ol><br />
<ol> Ask the speaker if there are any particular things that the speaker would like feedback on (e.g. pacing, boardwork, clarity of voice, etc.). </ol><br />
The partner would also take notes during the feedback session, to give the speaker a record of the conversation.<br />
</li><br />
<br />
This is very much an experiment, and while it might be intimidating at first, I actually think it could really help everyone (the speakers and the audience members too).</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Reading_Seminar_2018-19&diff=17068Reading Seminar 2018-192019-02-28T17:48:44Z<p>Rdavis: </p>
<hr />
<div>==Overview==<br />
My (Daniel's) experience has been that reading seminars have diminishing returns: they run out of steam after about 8 lectures on a certain book, as everyone starts falling behind, etc. I was thinking aim broader (rather than deeper), covering 3 books, but with fewer lectures. My idea is to partly cover: Beauville's "Complex Algebraic Surfaces"; Atiyah's "K-theory" (1989 edition); and Harris and Morrison's "Moduli of Curves". We would do about 6-8 lectures on each. This allows us to reboot every two months, which I hope will be mentally refreshing and will allow people who have lost the thread of the book to rejoin. Anyways, it's an experiment!<br />
<br />
Some notes:<br />
<ul><br />
<li>Here is lecture notes from Ravi Vakil on Complex Algebraic Surfaces "http://math.stanford.edu/~vakil/02-245/index.html"<br />
<li> Each book will have a co-organizer: Wanlin Li for Beauville's book; Michael Brown for Atiyah's book; and Rachel Davis for Harris and Mumford's book. Thanks!</li><br />
<li>I left some "Makeup" dates in the schedule with the idea that we would most likely take a week off on those dates. But if we need to miss another date (because of a conflict with a special colloquium or some other event), then we can use those as makeup slots.</li><br />
</ul><br />
<br />
We are experimenting with lots of new formats in this year's seminar. If you aren't happy with how the reading seminar is going, please let one of the organizers (Daniel, Wanlin, Michael, or Rachel) know and we will do our best to get things back on a helpful track.<br />
<br />
==Time and Location==<br />
Talks will be on Fridays from 11:00-11:45 in B329. This semester, Daniel is planning to keep a VERY HARD watch on the clock.<br />
<br />
== Talk Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | sections<br />
<br />
|-<br />
|September 7<br />
|Wanlin Li<br />
|Beauville I<br />
|-<br />
|September 14<br />
|Rachel Davis<br />
|Beauville II<br />
|-<br />
|September 21<br />
|Brandon Boggess<br />
|Beauville II and III<br />
|-<br />
|September 28<br />
|Mao Li<br />
|Beauville III<br />
|-<br />
|October 5<br />
|Wendy Cheng<br />
|Beauville IV<br />
|-<br />
|October 12<br />
|Soumya Sankar<br />
|Beauville V<br />
|-<br />
|October 19<br />
|David Wagner<br />
|Beauville V and VI<br />
|-<br />
|October 26<br />
|Dan Corey<br />
|Beauville VII and VIII<br />
|-<br />
|November 2<br />
|No Meeting<br />
|Break<br />
|-<br />
|November 9<br />
|Michael Brown<br />
|Atiyah 1 (Overview of goals of the seminar, Section 2.1) <br />
|-<br />
|November 16<br />
|Asvin Gothandaraman<br />
|Atiyah 2 (Section 2.2)<br />
|-<br />
|November 23<br />
|NO MEETING<br />
|Thanksgiving<br />
|-<br />
|November 30<br />
|NO MEETING<br />
|<br />
|-<br />
|SEMESETER BREAK<br />
|No meetings<br />
|<br />
|-<br />
|January 25<br />
|Daniel Erman<br />
|Atiyah 3 (Section 2.5: Examples)<br />
|-<br />
|February 1<br />
|Rachel Davis<br />
|Atiyah 4 (Section 2.3: Bott periodicity)<br />
|-<br />
|February 8<br />
|Michael Brown<br />
|Atiyah 5 (Thom isomorphism)<br />
|-<br />
|February 15<br />
|Mao Li<br />
|Algebraic K theory, Localization theorem and flag variety.<br />
|-<br />
|February 22<br />
|No Meeting<br />
|-<br />
|March 1<br />
|No Meeting<br />
|-<br />
|March 8<br />
| Juliette Bruce<br />
|Moduli 1<br />
|-<br />
|March 15<br />
|Niudun Wang<br />
|Moduli 2<br />
|-<br />
|March 22<br />
|NO MEETING<br />
|Spring recess<br />
|-<br />
|March 29<br />
|Rachel Davis<br />
|Moduli 3<br />
|-<br />
|April 5<br />
|Michael Brown<br />
|Moduli 4<br />
|-<br />
|April 12<br />
|Brandon Boggess<br />
|Moduli 5<br />
|-<br />
|April 19<br />
|??<br />
|Moduli 6<br />
|-<br />
|}<br />
<br />
==How to plan your talk==<br />
One key to giving good talks in a reading seminar is to know how to refocus the material that you read. Instead of going through the chapter lemma by lemma, you should ask: What is the main idea in this section? It could be a theorem, a definition, or even an example. But after reading the section, decide what the most important idea is and be sure to highlight early on.<br />
<br />
You will probably need to skip the proofs--and even the statements--of many of the lemmas and other results in the chapter. This is a good thing! The reason someone attends a talk, as opposed to just reading the material on their own, is because they want to see the material from the perspective of someone who has thought it about carefully.<br />
<br />
Also, make sure to give clear examples.<br />
<br />
<br />
==Feedback on talks==<br />
One of the goals for this semester is to help the speakers learn to give better talks. Here is our plan:<br />
<br />
<li> Feedback session: This is like a streamlined version of what creative writing workshops do. Every week, we reserve 15 minutes (12:35-12:50) for the entire audience to critique that week’s speaker. Comments will be friendly and constructive. A key rule is that the speaker is not allowed to speak until the last 5 minutes.</li><br />
<br />
<li> Partner: We assign a “partner” each week (usually the previous week's speaker). The partner will meet for 20-30 minutes with the speaker in advance to:<br />
<ol> Discuss a plan for the talk. Here the speaker can outline what they see as the main ideas, and the partner can share any wisdom gleaned from their experience the previous week. </ol><br />
<ol> Ask the speaker if there are any particular things that the speaker would like feedback on (e.g. pacing, boardwork, clarity of voice, etc.). </ol><br />
The partner would also take notes during the feedback session, to give the speaker a record of the conversation.<br />
</li><br />
<br />
This is very much an experiment, and while it might be intimidating at first, I actually think it could really help everyone (the speakers and the audience members too).</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Reading_Seminar_2018-19&diff=16316Reading Seminar 2018-192018-10-30T13:06:34Z<p>Rdavis: /* Talk Schedule */</p>
<hr />
<div>==Overview==<br />
My (Daniel's) experience has been that reading seminars have diminishing returns: they run out of steam after about 8 lectures on a certain book, as everyone starts falling behind, etc. I was thinking aim broader (rather than deeper), covering 3 books, but with fewer lectures. My idea is to partly cover: Beauville's "Complex Algebraic Surfaces"; Atiyah's "K-theory" (1989 edition); and Harris and Morrison's "Moduli of Curves". We would do about 6-8 lectures on each. This allows us to reboot every two months, which I hope will be mentally refreshing and will allow people who have lost the thread of the book to rejoin. Anyways, it's an experiment!<br />
<br />
Some notes:<br />
<ul><br />
<li>Here is lecture notes from Ravi Vakil on Complex Algebraic Surfaces "http://math.stanford.edu/~vakil/02-245/index.html"<br />
<li> Each book will have a co-organizer: Wanlin Li for Beauville's book; Michael Brown for Atiyah's book; and Rachel Davis for Harris and Mumford's book. Thanks!</li><br />
<li>I left some "Makeup" dates in the schedule with the idea that we would most likely take a week off on those dates. But if we need to miss another date (because of a conflict with a special colloquium or some other event), then we can use those as makeup slots.</li><br />
</ul><br />
<br />
We are experimenting with lots of new formats in this year's seminar. If you aren't happy with how the reading seminar is going, please let one of the organizers (Daniel, Wanlin, Michael, or Rachel) know and we will do our best to get things back on a helpful track.<br />
<br />
==Time and Location==<br />
Talks will be on Fridays from 11:45-12:35 in B325. This semester, Daniel is planning to keep a VERY HARD watch on the clock.<br />
<br />
== Talk Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | sections<br />
<br />
|-<br />
|September 7<br />
|Wanlin Li<br />
|Beauville I<br />
|-<br />
|September 14<br />
|Rachel Davis<br />
|Beauville II<br />
|-<br />
|September 21<br />
|Brandon Boggess<br />
|Beauville II and III<br />
|-<br />
|September 28<br />
|Mao Li<br />
|Beauville III<br />
|-<br />
|October 5<br />
|Wendy Cheng<br />
|Beauville IV<br />
|-<br />
|October 12<br />
|Soumya Sankar<br />
|Beauville V<br />
|-<br />
|October 19<br />
|David Wagner<br />
|Beauville V and VI<br />
|-<br />
|October 26<br />
|Dan Corey<br />
|Beauville VII and VIII<br />
|-<br />
|November 2<br />
|No Meeting<br />
|Break<br />
|-<br />
|November 9<br />
|Michael Brown<br />
|Atiyah 1 (Overview of goals of the seminar, Section 2.1) <br />
|-<br />
|November 16<br />
|Asvin Gothandaraman<br />
|Atiyah 2 (Section 2.2)<br />
|-<br />
|November 23<br />
|NO MEETING<br />
|Thanksgiving<br />
|-<br />
|November 30<br />
|Daniel Erman<br />
|Atiyah 3 (Section 2.5)<br />
|-<br />
|SEMESETER BREAK<br />
|No meetings<br />
|<br />
|-<br />
|January 25<br />
|Rachel Davis<br />
|Atiyah 4 (Section 2.3, Part 1)<br />
|-<br />
|February 1<br />
|??<br />
|Atiyah 5 (Section 2.3, Part 2)<br />
|-<br />
|February 8<br />
|??<br />
|Atiyah 6 (Section 2.6)<br />
|-<br />
|February 15<br />
|??<br />
|Atiyah 7 (Section 2.7, up to the Thom Isomorphism Theorem)<br />
|-<br />
|February 22<br />
|??<br />
|Makeup<br />
|-<br />
|March 1<br />
| Juliette Bruce<br />
|Moduli 1<br />
|-<br />
|March 8<br />
|Niudun Wang<br />
|Moduli 2<br />
|-<br />
|March 15<br />
|Rachel Davis<br />
|Moduli 3<br />
|-<br />
|March 22<br />
|NO MEETING<br />
|Spring recess<br />
|-<br />
|March 29<br />
|??<br />
|Moduli 4<br />
|-<br />
|April 5<br />
|??<br />
|Moduli 5<br />
|-<br />
|April 12<br />
|??<br />
|Moduli 6<br />
|-<br />
|April 19<br />
|??<br />
|Moduli 7<br />
|}<br />
<br />
==How to plan your talk==<br />
One key to giving good talks in a reading seminar is to know how to refocus the material that you read. Instead of going through the chapter lemma by lemma, you should ask: What is the main idea in this section? It could be a theorem, a definition, or even an example. But after reading the section, decide what the most important idea is and be sure to highlight early on.<br />
<br />
You will probably need to skip the proofs--and even the statements--of many of the lemmas and other results in the chapter. This is a good thing! The reason someone attends a talk, as opposed to just reading the material on their own, is because they want to see the material from the perspective of someone who has thought it about carefully.<br />
<br />
Also, make sure to give clear examples.<br />
<br />
<br />
==Feedback on talks==<br />
One of the goals for this semester is to help the speakers learn to give better talks. Here is our plan:<br />
<br />
<li> Feedback session: This is like a streamlined version of what creative writing workshops do. Every week, we reserve 15 minutes (12:35-12:50) for the entire audience to critique that week’s speaker. Comments will be friendly and constructive. A key rule is that the speaker is not allowed to speak until the last 5 minutes.</li><br />
<br />
<li> Partner: We assign a “partner” each week (usually the previous week's speaker). The partner will meet for 20-30 minutes with the speaker in advance to:<br />
<ol> Discuss a plan for the talk. Here the speaker can outline what they see as the main ideas, and the partner can share any wisdom gleaned from their experience the previous week. </ol><br />
<ol> Ask the speaker if there are any particular things that the speaker would like feedback on (e.g. pacing, boardwork, clarity of voice, etc.). </ol><br />
The partner would also take notes during the feedback session, to give the speaker a record of the conversation.<br />
</li><br />
<br />
This is very much an experiment, and while it might be intimidating at first, I actually think it could really help everyone (the speakers and the audience members too).</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Reading_Seminar_2018-19&diff=16264Reading Seminar 2018-192018-10-24T18:53:27Z<p>Rdavis: </p>
<hr />
<div>==Overview==<br />
My (Daniel's) experience has been that reading seminars have diminishing returns: they run out of steam after about 8 lectures on a certain book, as everyone starts falling behind, etc. I was thinking aim broader (rather than deeper), covering 3 books, but with fewer lectures. My idea is to partly cover: Beauville's "Complex Algebraic Surfaces"; Atiyah's "K-theory" (1989 edition); and Harris and Morrison's "Moduli of Curves". We would do about 6-8 lectures on each. This allows us to reboot every two months, which I hope will be mentally refreshing and will allow people who have lost the thread of the book to rejoin. Anyways, it's an experiment!<br />
<br />
Some notes:<br />
<ul><br />
<li>Here is lecture notes from Ravi Vakil on Complex Algebraic Surfaces "http://math.stanford.edu/~vakil/02-245/index.html"<br />
<li> Each book will have a co-organizer: Wanlin Li for Beauville's book; Michael Brown for Atiyah's book; and Rachel Davis for Harris and Mumford's book. Thanks!</li><br />
<li>I left some "Makeup" dates in the schedule with the idea that we would most likely take a week off on those dates. But if we need to miss another date (because of a conflict with a special colloquium or some other event), then we can use those as makeup slots.</li><br />
</ul><br />
<br />
We are experimenting with lots of new formats in this year's seminar. If you aren't happy with how the reading seminar is going, please let one of the organizers (Daniel, Wanlin, Michael, or Rachel) know and we will do our best to get things back on a helpful track.<br />
<br />
==Time and Location==<br />
Talks will be on Fridays from 11:45-12:35 in B325. This semester, Daniel is planning to keep a VERY HARD watch on the clock.<br />
<br />
== Talk Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | sections<br />
<br />
|-<br />
|September 7<br />
|Wanlin Li<br />
|Beauville I<br />
|-<br />
|September 14<br />
|Rachel Davis<br />
|Beauville II<br />
|-<br />
|September 21<br />
|Brandon Boggess<br />
|Beauville II and III<br />
|-<br />
|September 28<br />
|Mao Li<br />
|Beauville III<br />
|-<br />
|October 5<br />
|Wendy Cheng<br />
|Beauville IV<br />
|-<br />
|October 12<br />
|Soumya Sankar<br />
|Beauville V<br />
|-<br />
|October 19<br />
|David Wagner<br />
|Beauville V and VI<br />
|-<br />
|October 26<br />
|Dan Corey<br />
|Beauville VII and VIII<br />
|-<br />
|November 2<br />
|??<br />
|Makeup Beauville<br />
|-<br />
|November 9<br />
|Michael Brown<br />
|Atiyah 1 (Overview of goals of the seminar, Section 2.1) <br />
|-<br />
|November 16<br />
|Asvin Gothandaraman<br />
|Atiyah 2 (Section 2.2)<br />
|-<br />
|November 23<br />
|NO MEETING<br />
|Thanksgiving<br />
|-<br />
|November 30<br />
|Daniel Erman<br />
|Atiyah 3 (Section 2.5)<br />
|-<br />
|SEMESETER BREAK<br />
|No meetings<br />
|<br />
|-<br />
|January 25<br />
|Rachel Davis<br />
|Atiyah 4 (Section 2.3, Part 1)<br />
|-<br />
|February 1<br />
|??<br />
|Atiyah 5 (Section 2.3, Part 2)<br />
|-<br />
|February 8<br />
|??<br />
|Atiyah 6 (Section 2.6)<br />
|-<br />
|February 15<br />
|??<br />
|Atiyah 7 (Section 2.7, up to the Thom Isomorphism Theorem)<br />
|-<br />
|February 22<br />
|??<br />
|Makeup<br />
|-<br />
|March 1<br />
| Juliette Bruce<br />
|Moduli 1<br />
|-<br />
|March 8<br />
|Niudun Wang<br />
|Moduli 2<br />
|-<br />
|March 15<br />
|Rachel Davis<br />
|Moduli 3<br />
|-<br />
|March 22<br />
|Spring recess<br />
|No meeting <br />
|-<br />
|March 29<br />
|??<br />
|Moduli 4<br />
|-<br />
|April 5<br />
|??<br />
|Moduli 5<br />
|-<br />
|April 12<br />
|??<br />
|Moduli 6<br />
|-<br />
|April 19<br />
|??<br />
|Moduli 7<br />
|}<br />
<br />
==How to plan your talk==<br />
One key to giving good talks in a reading seminar is to know how to refocus the material that you read. Instead of going through the chapter lemma by lemma, you should ask: What is the main idea in this section? It could be a theorem, a definition, or even an example. But after reading the section, decide what the most important idea is and be sure to highlight early on.<br />
<br />
You will probably need to skip the proofs--and even the statements--of many of the lemmas and other results in the chapter. This is a good thing! The reason someone attends a talk, as opposed to just reading the material on their own, is because they want to see the material from the perspective of someone who has thought it about carefully.<br />
<br />
Also, make sure to give clear examples.<br />
<br />
<br />
==Feedback on talks==<br />
One of the goals for this semester is to help the speakers learn to give better talks. Here is our plan:<br />
<br />
<li> Feedback session: This is like a streamlined version of what creative writing workshops do. Every week, we reserve 15 minutes (12:35-12:50) for the entire audience to critique that week’s speaker. Comments will be friendly and constructive. A key rule is that the speaker is not allowed to speak until the last 5 minutes.</li><br />
<br />
<li> Partner: We assign a “partner” each week (usually the previous week's speaker). The partner will meet for 20-30 minutes with the speaker in advance to:<br />
<ol> Discuss a plan for the talk. Here the speaker can outline what they see as the main ideas, and the partner can share any wisdom gleaned from their experience the previous week. </ol><br />
<ol> Ask the speaker if there are any particular things that the speaker would like feedback on (e.g. pacing, boardwork, clarity of voice, etc.). </ol><br />
The partner would also take notes during the feedback session, to give the speaker a record of the conversation.<br />
</li><br />
<br />
This is very much an experiment, and while it might be intimidating at first, I actually think it could really help everyone (the speakers and the audience members too).</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Algebra_and_Algebraic_Geometry_Seminar_Spring_2018&diff=16226Algebra and Algebraic Geometry Seminar Spring 20182018-10-19T13:56:20Z<p>Rdavis: </p>
<hr />
<div>The seminar meets on Fridays at 2:25 pm in room B235.<br />
<br />
Here is the schedule for [[Algebraic Geometry Seminar Spring 2017 | the previous semester]], [[Algebra and Algebraic Geometry Seminar Fall 2018 | the next semester]], and for [[Algebra and Algebraic Geometry Seminar | this semester]]. <br />
<br />
==Algebra and Algebraic Geometry Mailing List==<br />
<br />
<br />
*Please join the [https://admin.lists.wisc.edu/index.php?p=11&l=ags AGS Mailing List] to hear about upcoming seminars, lunches, and other algebraic geometry events in the department (it is possible you must be on a math department computer to use this link).<br />
<br />
<br />
== Fall 2018 Schedule ==<br />
<br />
[[Algebra and Algebraic Geometry Seminar Fall 2018 | Fall 2018 schedule]]<br />
<br />
== Spring 2018 Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s) <br />
<br />
|-<br />
|January 26<br />
|[http://homepages.math.uic.edu/~tmoulinos/ Tasos Moulinos (UIC)] <br />
|[[#Tasos Moulinos|Derived Azumaya Algebras and Twisted K-theory]]<br />
|Michael<br />
|-<br />
|February 2<br />
|Daniel Erman (Wisconsin) <br />
|[[#Daniel Erman|TBA]]<br />
|Local<br />
|-<br />
|'''February 8''' 2:30-3:30 in VV B113<br />
|[http://www.mathematics.pitt.edu/person/roman-fedorov/ Roman Fedorov (University of Pittsburgh)]<br />
|[[#Roman Fedorov|A conjecture of Grothendieck and Serre on principal bundles in mixed characteristic]]<br />
|Dima<br />
|-<br />
|February 9<br />
|Juliette Bruce (Wisconsin) <br />
|[[#Juliette Bruce|Asymptotic Syzygies in the Semi-Ample Setting ]]<br />
|Local<br />
|-<br />
|February 16<br />
|[http://www.math.wisc.edu/~andreic/ Andrei Caldararu (Wisconsin)]<br />
|[[#Andrei Caldararu|Computing a categorical Gromov-Witten invariant]]<br />
|Local<br />
|-<br />
|February 23<br />
|Aron Heleodoro (Northwestern) <br />
|[[#Aron Heleodoro|Normally ordered tensor product of Tate objects and decomposition of higher adeles]]<br />
|Dima<br />
|-<br />
|March 2<br />
|Moisés Herradón Cueto (Wisconsin)<br />
|[[#Moisés Herradón Cueto|Local type of difference equations]]<br />
|Local<br />
|-<br />
|March 9<br />
|Eva Elduque (Wisconsin)<br />
|[[#Eva Elduque|On the signed Euler characteristic property for subvarieties of Abelian varieties]]<br />
|Local<br />
|-<br />
|March 16<br />
|[https://math.berkeley.edu/~chenhi/ Harrison Chen (Berkeley)]<br />
|[[#Harrison Chen|Equivariant localization for periodic cyclic homology and derived loop spaces]]<br />
|Andrei<br />
|-<br />
|March 23<br />
|[http://www-personal.umich.edu/~ptoste/ Phil Tosteson (Michigan)]<br />
|[[#Phil Tosteson|Stability in the homology of Deligne-Mumford compactifications]]<br />
|Steven<br />
|-<br />
|-<br />
|April 6<br />
|[http://www-personal.umich.edu/~weiho/ Wei Ho (Michigan)]<br />
|Noncommutative Galois closures and moduli problems<br />
|Daniel/Wanlin<br />
|-<br />
|-<br />
|April 13<br />
|[https://sites.google.com/site/dcorey2814/ Daniel Corey (Yale)]<br />
|[#Corey|Initial degenerations of Grassmannians]<br />
|Daniel<br />
|-<br />
|April 20<br />
|Alena Pirutka (NYU)<br />
|[[#Alena Pirutka|Irrationality problems]]<br />
|Jordan<br />
|-<br />
|'''April 23''' 2:30-3:30 at 225 Ingraham<br />
|Nero Budur (Leuven)<br />
|[[#Nero Budur|Homotopy of singular algebraic varieties]]<br />
|Botong<br />
|-<br />
|April 27<br />
|Alexander Yom Din (Caltech) <br />
|[[#Alexander Yom Din|Drinfeld-Gaitsgory functor and contragradient duality for (g,K)-modules]]<br />
|Dima<br />
|-<br />
|May 4<br />
|John Lesieutre (UIC) <br />
|[[#John Lesieutre|Some higher-dimensional cases of the Kawaguchi-Silverman conjecture]]<br />
|Daniel<br />
|}<br />
<br />
== Abstracts ==<br />
<br />
===Tasos Moulinos===<br />
<br />
'''Derived Azumaya Algebras and Twisted K-theory'''<br />
<br />
Topological K-theory of dg-categories is a localizing invariant of dg-categories over <math> \mathbb{C} </math><br />
taking values in the <math> \infty </math>-category of <math> KU </math>-modules. In this talk I describe a relative version<br />
of this construction; namely for <math>X</math> a quasi-compact, quasi-separated <math> \mathbb{C} </math>-scheme I construct a<br />
functor valued in the <math> \infty </math>-category of sheaves of spectra on <math> X(\mathbb{C}) </math>, the complex points of <math>X</math>. For inputs<br />
of the form <math>\operatorname{Perf}(X, A)</math> where <math>A</math> is an Azumaya algebra over <math>X</math>, I characterize the values<br />
of this functor in terms of the twisted topological K-theory of <math> X(\mathbb{C}) </math>. From this I deduce<br />
a certain decomposition, for <math> X </math> a finite CW-complex equipped with a bundle <math> P </math> of projective<br />
spaces over <math> X </math>, of <math> KU(P) </math> in terms of the twisted topological K-theory of <math> X </math> ; this is<br />
a topological analogue of a result of Quillen’s on the algebraic K-theory of Severi-Brauer<br />
schemes.<br />
<br />
===Roman Fedorov===<br />
<br />
'''A conjecture of Grothendieck and Serre on principal bundles in mixed<br />
characteristic'''<br />
<br />
Let G be a reductive group scheme over a regular local ring R. An old<br />
conjecture of Grothendieck and Serre predicts that such a principal<br />
bundle is trivial, if it is trivial over the fraction field of R. The<br />
conjecture has recently been proved in the "geometric" case, that is,<br />
when R contains a field. In the remaining case, the difficulty comes<br />
from the fact, that the situation is more rigid, so that a certain<br />
general position argument does not go through. I will discuss this<br />
difficulty and a way to circumvent it to obtain some partial results.<br />
<br />
===Juliette Bruce===<br />
<br />
'''Asymptotic Syzygies in the Semi-Ample Setting'''<br />
<br />
In recent years numerous conjectures have been made describing the asymptotic Betti numbers of a projective variety as the embedding line bundle becomes more ample. I will discuss recent work attempting to generalize these conjectures to the case when the embedding line bundle becomes more semi-ample. (Recall a line bundle is semi-ample if a sufficiently large multiple is base point free.) In particular, I will discuss how the monomial methods of Ein, Erman, and Lazarsfeld used to prove non-vanishing results on projective space can be extended to prove non-vanishing results for products of projective space.<br />
<br />
===Andrei Caldararu===<br />
<br />
'''Computing a categorical Gromov-Witten invariant'''<br />
<br />
In his 2005 paper "The Gromov-Witten potential associated to a TCFT" Kevin Costello described a procedure for recovering an analogue of the Gromov-Witten potential directly out of a cyclic A-inifinity algebra or category. Applying his construction to the derived category of sheaves of a complex projective variety provides a definition of higher genus B-model Gromov-Witten invariants, independent of the BCOV formalism. This has several advantages. Due to the categorical invariance of these invariants, categorical mirror symmetry automatically implies classical mirror symmetry to all genera. Also, the construction can be applied to other categories like categories of matrix factorization, giving a direct definition of FJRW invariants, for example.<br />
<br />
In my talk I shall describe the details of the computation (joint with Junwu Tu) of the invariant, at g=1, n=1, for elliptic curves. The result agrees with the predictions of mirror symmetry, matching classical calculations of Dijkgraaf. It is the first non-trivial computation of a categorical Gromov-Witten invariant.<br />
<br />
===Aron Heleodoro===<br />
<br />
'''Normally ordered tensor product of Tate objects and decomposition of higher adeles'''<br />
<br />
In this talk I will introduce the different tensor products that exist on Tate objects over vector spaces (or more generally coherent sheaves on a given scheme). As an application, I will explain how these can be used to describe higher adeles on an n-dimensional smooth scheme. Both Tate objects and higher adeles would be introduced in the talk. (This is based on joint work with Braunling, Groechenig and Wolfson.)<br />
<br />
===Moisés Herradón Cueto===<br />
<br />
'''Local type of difference equations'''<br />
<br />
The theory of algebraic differential equations on the affine line is very well-understood. In particular, there is a well-defined notion of restricting a D-module to a formal neighborhood of a point, and these restrictions are completely described by two vector spaces, called vanishing cycles and nearby cycles, and some maps between them. We give an analogous notion of "restriction to a formal disk" for difference equations that satisfies several desirable properties: first of all, a difference module can be recovered uniquely from its restriction to the complement of a point and its restriction to a formal disk around this point. Secondly, it gives rise to a local Mellin transform, which relates vanishing cycles of a difference module to nearby cycles of its Mellin transform. Since the Mellin transform of a difference module is a D-module, the Mellin transform brings us back to the familiar world of D-modules.<br />
<br />
===Eva Elduque===<br />
<br />
'''On the signed Euler characteristic property for subvarieties of Abelian varieties'''<br />
<br />
Franecki and Kapranov proved that the Euler characteristic of a perverse sheaf on a semi-abelian variety is non-negative. This result has several purely topological consequences regarding the sign of the (topological and intersection homology) Euler characteristic of a subvariety of an abelian variety, and it is natural to attempt to justify them by more elementary methods. In this talk, we'll explore the geometric tools used recently in the proof of the signed Euler<br />
characteristic property. Joint work with Christian Geske and Laurentiu Maxim.<br />
<br />
===Harrison Chen===<br />
<br />
'''Equivariant localization for periodic cyclic homology and derived loop spaces'''<br />
<br />
There is a close relationship between derived loop spaces, a geometric object, and (periodic) cyclic homology, a categorical invariant. In this talk we will discuss this relationship and how it leads to an equivariant localization result, which has an intuitive interpretation using the language of derived loop spaces. We discuss ongoing generalizations and potential applications in computing the periodic cyclic homology of categories of equivariant (coherent) sheaves on algebraic varieties.<br />
<br />
===Phil Tosteson===<br />
<br />
'''Stability in the homology of Deligne-Mumford compactifications'''<br />
<br />
The space <math>\bar M_{g,n}</math> is a compactification of the moduli space algebraic curves with marked points, obtained by allowing smooth curves to degenerate to nodal ones. We will talk about how the asymptotic behavior of its homology, <math>H_i(\bar M_{g,n})</math>, for <math>n \gg 0</math> can be studied using the representation theory of the category of finite sets and surjections.<br />
<br />
===Wei Ho===<br />
<br />
'''Noncommutative Galois closures and moduli problems'''<br />
<br />
In this talk, we will discuss the notion of a Galois closure for a possibly noncommutative algebra. We will explain how this problem is related to certain moduli problems involving genus one curves and torsors for Jacobians of higher genus curves. This is joint work with Matt Satriano.<br />
<br />
===Daniel Corey===<br />
<br />
'''Initial degenerations of Grassmannians'''<br />
<br />
Let Gr_0(d,n) denote the open subvariety of the Grassmannian Gr(d,n) consisting of d-1 dimensional subspaces of P^{n-1} meeting the toric boundary transversely. We prove that Gr_0(3,7) is schoen in the sense that all of its initial degenerations are smooth. The main technique we will use is to express the initial degenerations of Gr_0(3,7) as a inverse limit of thin Schubert cells. We use this to show that the Chow quotient of Gr(3,7) by the maximal torus H in GL(7) is the log canonical compactification of the moduli space of 7 lines in P^2 in linear general position.<br />
<br />
===Alena Pirutka===<br />
<br />
'''Irrationality problems'''<br />
<br />
Let X be a projective algebraic variety, the set of solutions of a system of homogeneous polynomial equations. Several classical notions describe how ``unconstrained'' the solutions are, i.e., how close X is to projective space: there are notions of rational, unirational and stably rational varieties. Over the field of complex numbers, these notions coincide in dimensions one and two, but diverge in higher<br />
dimensions. In the last years, many new classes of non stably rational varieties were found, using a specialization technique, introduced by C. Voisin. This method also allowed to prove that the rationality is not a deformation invariant in smooth and projective families of complex varieties: this is a joint work with B. Hassett and Y. Tschinkel. In my talk I will describe classical examples, as well as the recent progress around these rationality questions.<br />
<br />
===Nero Budur===<br />
<br />
'''Homotopy of singular algebraic varieties'''<br />
<br />
By work of Simpson, Kollár, Kapovich, every finitely generated group can be the fundamental group of an irreducible complex algebraic variety with only normal crossings and Whitney umbrellas as singularities. In contrast, we show that if a complex algebraic variety has no weight zero 1-cohomology classes, then the fundamental group is strongly restricted: the irreducible components of the cohomology jump loci of rank one local systems containing the constant sheaf are complex affine tori. Same for links and Milnor fibers. This is joint work with Marcel Rubió.<br />
<br />
<br />
===Alexander Yom Din===<br />
<br />
'''Drinfeld-Gaitsgory functor and contragradient duality for (g,K)-modules'''<br />
<br />
Drinfeld suggested the definition of a certain endo-functor, called the pseudo-identity functor (or the Drinfeld-Gaitsgory functor), on the category of D-modules on an algebraic stack. We extend this definition to an arbitrary DG category, and show that if certain finiteness conditions are satisfied, this functor is the inverse of the Serre functor. We show that the pseudo-identity functor for (g,K)-modules is isomorphic to the composition of cohomological and contragredient dualities, which is parallel to an analogous assertion for p-adic groups.<br />
<br />
In this talk I will try to discuss some of these results and around them. This is joint work with Dennis Gaitsgory.<br />
<br />
===John Lesieutre===<br />
'''Some higher-dimensional cases of the Kawaguchi-Silverman conjecture'''<br />
<br />
Given a dominant rational self-map f : X -->X of a variety defined over a number field, the first dynamical degree $\lambda_1(f)$ and the arithmetic degree $\alpha_f(P)$ are two measures of the complexity of the dynamics of f: the first measures the rate of growth of the degrees of the iterates f^n, while the second measures the rate of growth of the heights of the iterates f^n(P) for a point P. A conjecture of Kawaguchi and Silverman predicts that if P has Zariski-dense orbit, then these two quantities coincide. I will prove this conjecture in several higher-dimensional settings, including for all automorphisms of hyper-K\"ahler varieties. This is joint work with Matthew Satriano.</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Algebra_and_Algebraic_Geometry_Seminar_Fall_2018&diff=15977Algebra and Algebraic Geometry Seminar Fall 20182018-09-13T14:11:26Z<p>Rdavis: </p>
<hr />
<div>The seminar meets on Fridays at 2:25 pm in room B235.<br />
<br />
Here is the schedule for [[Algebra and Algebraic Geometry Seminar Spring 2018 | the previous semester]], [[Algebra and Algebraic Geometry Seminar Spring 2019 | the next semester]], and for [[Algebra and Algebraic Geometry Seminar | this semester]].<br />
<br />
==Algebra and Algebraic Geometry Mailing List==<br />
<br />
<br />
*Please join the [https://admin.lists.wisc.edu/index.php?p=11&l=ags AGS Mailing List] to hear about upcoming seminars, lunches, and other algebraic geometry events in the department (it is possible you must be on a math department computer to use this link).<br />
<br />
== Fall 2018 Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s) <br />
<br />
|-<br />
|September 7<br />
|Daniel Erman<br />
|Big Polynomial Rings<br />
|Local<br />
|-<br />
|September 14<br />
|Akhil Mathew (U Chicago)<br />
|Kaledin's noncommutative degeneration theorem and topological Hochschild homology<br />
|Andrei<br />
|-<br />
|September 21<br />
|Andrei Caldararu<br />
|TBA<br />
|Local<br />
|-<br />
|September 28<br />
|Mark Walker (Nebraska)<br />
|TBD<br />
|Michael and Daniel<br />
|-<br />
|October 5<br />
|-<br />
|-<br />
|-<br />
|-<br />
|October 12<br />
|Jose Rodriguez (Wisconsin)<br />
|TBD<br />
|Local<br />
|-<br />
|October 19<br />
|Oleksandr Tsymbaliuk (Yale)<br />
|TBD<br />
|Paul Terwilliger<br />
|-<br />
|October 26<br />
|<br />
|<br />
|<br />
|-<br />
|November 2<br />
|Behrouz Taji (Notre Dame)<br />
|TBD<br />
|Botong Wang<br />
|-<br />
|November 9<br />
|Juliette Bruce<br />
|TBD<br />
|Local<br />
|-<br />
|November 16<br />
|Wanlin Li<br />
|TBD<br />
|Local<br />
|-<br />
|November 23<br />
|Thanksgiving<br />
|No Seminar<br />
|<br />
|-<br />
|November 30<br />
|[http://www-personal.umich.edu/~grifo/ Eloísa Grifo] (Michigan)<br />
|TBD<br />
|Daniel<br />
|-<br />
|December 7<br />
|Michael Brown<br />
|TBD<br />
|Local<br />
|-<br />
|December 14<br />
|John Wiltshire-Gordon<br />
|TBD<br />
|Local<br />
|-<br />
|}<br />
<br />
== Abstracts ==<br />
<br />
===Akhil Mathew===<br />
<br />
'''Title: Kaledin's noncommutative degeneration theorem and topological Hochschild homology'''<br />
<br />
For a smooth proper variety over a field of characteristic<br />
zero, the Hodge-to-de Rham spectral sequence (relating the cohomology<br />
of differential forms to de Rham cohomology) is well-known to<br />
degenerate, via Hodge theory. A "noncommutative" version of this<br />
theorem has been proved by Kaledin for smooth proper dg categories<br />
over a field of characteristic zero, based on the technique of<br />
reduction mod p. I will describe a short proof of this theorem using<br />
the theory of topological Hochschild homology, which provides a<br />
canonical one-parameter deformation of Hochschild homology in<br />
characteristic p.</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Colloquia/Fall18&diff=15484Colloquia/Fall182018-04-30T15:46:12Z<p>Rdavis: </p>
<hr />
<div>= Mathematics Colloquium =<br />
<br />
All colloquia are on Fridays at 4:00 pm in Van Vleck B239, '''unless otherwise indicated'''.<br />
<br />
== Spring 2018 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date <br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
|-<br />
|January 29 (Monday)<br />
| [http://www.math.columbia.edu/~chaoli/ Li Chao] (Columbia)<br />
|[[#January 29 Li Chao (Columbia)| Elliptic curves and Goldfeld's conjecture ]]<br />
| Jordan Ellenberg<br />
|<br />
|-<br />
|February 2 (Room: 911)<br />
| [https://scholar.harvard.edu/tfai/home Thomas Fai] (Harvard)<br />
|[[#February 2 Thomas Fai (Harvard)| The Lubricated Immersed Boundary Method ]]<br />
| Spagnolie, Smith<br />
|<br />
|-<br />
|February 5 (Monday, Room: 911)<br />
| [http://www.ma.huji.ac.il/~alexlub/ Alex Lubotzky] (Hebrew University) <br />
|[[#February 5 Alex Lubotzky (Hebrew University)| High dimensional expanders: From Ramanujan graphs to Ramanujan complexes ]]<br />
| Ellenberg, Gurevitch<br />
|<br />
|-<br />
|February 6 (Tuesday 2 pm, Room 911)<br />
| [http://www.ma.huji.ac.il/~alexlub/ Alex Lubotzky] (Hebrew University) <br />
|[[#February 6 Alex Lubotzky (Hebrew University)| Groups' approximation, stability and high dimensional expanders ]]<br />
| Ellenberg, Gurevitch<br />
|<br />
|-<br />
|February 9<br />
| [http://www.math.cmu.edu/~wes/ Wes Pegden] (CMU)<br />
|[[#February 9 Wes Pegden (CMU)| The fractal nature of the Abelian Sandpile ]]<br />
| Roch<br />
|<br />
|-<br />
|March 2<br />
| [http://www.math.utah.edu/~bertram/ Aaron Bertram] (University of Utah)<br />
|[[#March 2 Aaron Bertram (Utah)| Stability in Algebraic Geometry ]]<br />
| Caldararu<br />
|<br />
|-<br />
| March 16 (Room: 911)<br />
|[https://math.dartmouth.edu/~annegelb/ Anne Gelb] (Dartmouth)<br />
|[[#March 16 Anne Gelb (Dartmouth)| Reducing the effects of bad data measurements using variance based weighted joint sparsity ]]<br />
| WIMAW<br />
|<br />
|-<br />
|April 5 (Thursday, Room: 911)<br />
| [http://math.ucr.edu/home/baez/ John Baez] (UC Riverside)<br />
|[[#April 5 John Baez (UC Riverside)| Monoidal categories of networks ]]<br />
| Craciun<br />
|<br />
|-<br />
| April 6<br />
| [https://www.math.purdue.edu/~egoins Edray Goins] (Purdue)<br />
|[[# Edray Goins| Toroidal Bely&#301; Pairs, Toroidal Graphs, and their Monodromy Groups ]]<br />
| Melanie<br />
|<br />
|-<br />
| April 13 (911 Van Vleck)<br />
| [https://www.math.brown.edu/~jpipher/ Jill Pipher] (Brown)<br />
|[[#April 13, Jill Pipher, Brown University| Mathematical ideas in cryptography ]]<br />
| WIMAW<br />
|<br />
|-<br />
| April 16 (Monday)<br />
| [http://www-users.math.umn.edu/~cberkesc/ Christine Berkesch Zamaere ] (University of Minnesota)<br />
|[[#April 16, Christine Berkesch Zamaere (University of Minnesota)| Free complexes on smooth toric varieties ]]<br />
| Erman, Sam<br />
|<br />
|-<br />
| April 25 (Wednesday, Room: 911)<br />
| [http://www.f.waseda.jp/hitoshi.ishii/ Hitoshi Ishii] (Tsuda University) Wasow lecture<br />
|[[#April 25, Hitoshi Ishii (Tsuda University)| Asymptotic problems for Hamilton-Jacobi equations and weak KAM theory ]]<br />
| Tran<br />
|<br />
|-<br />
| May 1 (Tuesday, 4:30pm, Room: B102 VV)<br />
| [https://math.uchicago.edu/~aneves/ Andre Neves] (University Chicago and Imperial College London) Distinguished lecture<br />
|[[#May 1, Andre Neves (University Chicago and Imperial College London)| Wow, so many minimal surfaces! (Part I)]]<br />
| Lu Wang<br />
|<br />
|-<br />
| May 2 (Wednesday, 3pm, Room: B325 VV)<br />
| [https://math.uchicago.edu/~aneves/ Andre Neves] (University of Chicago and Imperial College London) Distinguished lecture<br />
|[[#May 2, Andre Neves (University Chicago and Imperial College London)| Wow, so many minimal surfaces! (Part II) ]]<br />
| Lu Wang<br />
|<br />
|-<br />
| May 4<br />
| [http://math.mit.edu/~cohn/ Henry Cohn] (Microsoft Research and MIT)<br />
|[[# TBA| TBA ]]<br />
| Ellenberg<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|}<br />
<br />
== Spring Abstracts ==<br />
<br />
<br />
===January 29 Li Chao (Columbia)===<br />
<br />
Title: Elliptic curves and Goldfeld's conjecture<br />
<br />
Abstract: <br />
An elliptic curve is a plane curve defined by a cubic equation. Determining whether such an equation has infinitely many rational solutions has been a central problem in number theory for centuries, which lead to the celebrated conjecture of Birch and Swinnerton-Dyer. Within a family of elliptic curves (such as the Mordell curve family y^2=x^3-d), a conjecture of Goldfeld further predicts that there should be infinitely many rational solutions exactly half of the time. We will start with a history of this problem, discuss our recent work (with D. Kriz) towards Goldfeld's conjecture and illustrate the key ideas and ingredients behind these new progresses.<br />
<br />
=== February 2 Thomas Fai (Harvard) ===<br />
<br />
Title: The Lubricated Immersed Boundary Method<br />
<br />
Abstract:<br />
Many real-world examples of fluid-structure interaction, including the transit of red blood cells through the narrow slits in the spleen, involve the near-contact of elastic structures separated by thin layers of fluid. The separation of length scales between these fine lubrication layers and the larger elastic objects poses significant computational challenges. Motivated by the challenge of resolving such multiscale problems, we introduce an immersed boundary method that uses elements of lubrication theory to resolve thin fluid layers between immersed boundaries. We apply this method to two-dimensional flows of increasing complexity, including eccentric rotating cylinders and elastic vesicles near walls in shear flow, to show its increased accuracy compared to the classical immersed boundary method. We present preliminary simulation results of cell suspensions, a problem in which near-contact occurs at multiple levels, such as cell-wall, cell-cell, and intracellular interactions, to highlight the importance of resolving thin fluid layers in order to obtain the correct overall dynamics.<br />
<br />
===February 5 Alex Lubotzky (Hebrew University)===<br />
<br />
Title: High dimensional expanders: From Ramanujan graphs to Ramanujan complexes<br />
<br />
Abstract: <br />
<br />
Expander graphs in general, and Ramanujan graphs , in particular, have played a major role in computer science in the last 5 decades and more recently also in pure math. The first explicit construction of bounded degree expanding graphs was given by Margulis in the early 70's. In mid 80' Margulis and Lubotzky-Phillips-Sarnak provided Ramanujan graphs which are optimal such expanders. <br />
<br />
In recent years a high dimensional theory of expanders is emerging. A notion of topological expanders was defined by Gromov in 2010 who proved that the complete d-dimensional simplical complexes are such. He raised the basic question of existence of such bounded degree complexes of dimension d>1. <br />
<br />
This question was answered recently affirmatively (by T. Kaufman, D. Kazdhan and A. Lubotzky for d=2 and by S. Evra and T. Kaufman for general d) by showing that the d-skeleton of (d+1)-dimensional Ramanujan complexes provide such topological expanders. We will describe these developments and the general area of high dimensional expanders. <br />
<br />
<br />
===February 6 Alex Lubotzky (Hebrew University)===<br />
<br />
Title: Groups' approximation, stability and high dimensional expanders<br />
<br />
Abstract: <br />
<br />
Several well-known open questions, such as: are all groups sofic or hyperlinear?, have a common form: can all groups be approximated by asymptotic homomorphisms into the symmetric groups Sym(n) (in the sofic case) or the unitary groups U(n) (in the hyperlinear case)? In the case of U(n), the question can be asked with respect to different metrics and norms. We answer, for the first time, one of these versions, showing that there exist fintely presented groups which are not approximated by U(n) with respect to the Frobenius (=L_2) norm.<br />
<br />
The strategy is via the notion of "stability": some higher dimensional cohomology vanishing phenomena is proven to imply stability and using high dimensional expanders, it is shown that some non-residually finite groups (central extensions of some lattices in p-adic Lie groups) are Frobenious stable and hence cannot be Frobenius approximated. <br />
<br />
All notions will be explained. Joint work with M, De Chiffre, L. Glebsky and A. Thom.<br />
<br />
===February 9 Wes Pegden (CMU)===<br />
<br />
Title: The fractal nature of the Abelian Sandpile <br />
<br />
Abstract: The Abelian Sandpile is a simple diffusion process on the integer lattice, in which configurations of chips disperse according to a simple rule: when a vertex has at least 4 chips, it can distribute one chip to each neighbor. <br />
<br />
Introduced in the statistical physics community in the 1980s, the Abelian sandpile exhibits striking fractal behavior which long resisted rigorous mathematical analysis (or even a plausible explanation). We now have a relatively robust mathematical understanding of this fractal nature of the sandpile, which involves surprising connections between integer superharmonic functions on the lattice, discrete tilings of the plane, and Apollonian circle packings. In this talk, we will survey our work in this area, and discuss avenues of current and future research.<br />
<br />
===March 2 Aaron Bertram (Utah)===<br />
<br />
Title: Stability in Algebraic Geometry<br />
<br />
Abstract: Stability was originally introduced in algebraic geometry in the context of finding a projective quotient space for the action of an algebraic group on a projective manifold. This, in turn, led in the 1960s to a notion of slope-stability for vector bundles on a Riemann surface, which was an important tool in the classification of vector bundles. In the 1990s, mirror symmetry considerations led Michael Douglas to notions of stability for "D-branes" (on a higher-dimensional manifold) that corresponded to no previously known mathematical definition. We now understand each of these notions of stability as a distinct point of a complex "stability manifold" that is an important invariant of the (derived) category of complexes of vector bundles of a projective manifold. In this talk I want to give some examples to illustrate the various stabilities, and also to describe some current work in the area.<br />
<br />
===March 16 Anne Gelb (Dartmouth)===<br />
<br />
Title: Reducing the effects of bad data measurements using variance based weighted joint sparsity<br />
<br />
Abstract: We introduce the variance based joint sparsity (VBJS) method for sparse signal recovery and image reconstruction from multiple measurement vectors. Joint sparsity techniques employing $\ell_{2,1}$ minimization are typically used, but the algorithm is computationally intensive and requires fine tuning of parameters. The VBJS method uses a weighted $\ell_1$ joint sparsity algorithm, where the weights depend on the pixel-wise variance. The VBJS method is accurate, robust, cost efficient and also reduces the effects of false data.<br />
<br />
<br />
<br />
<br />
===April 5 John Baez (UC Riverside)===<br />
<br />
Title: Monoidal categories of networks<br />
<br />
Abstract: Nature and the world of human technology are full of networks. People like to draw diagrams of networks: flow charts, electrical circuit diagrams, chemical reaction networks, signal-flow graphs, Bayesian networks, food webs, Feynman diagrams and the like. Far from mere informal tools, many of these diagrammatic languages fit into a rigorous framework: category theory. I will explain a bit of how this works and discuss some applications.<br />
<br />
<br />
<br />
<br />
<br />
===April 6 Edray Goins (Purdue)===<br />
<br />
Title: Toroidal Bely&#301; Pairs, Toroidal Graphs, and their Monodromy Groups<br />
<br />
Abstract: A Bely&#301; map <math> \beta: \mathbb P^1(\mathbb C) \to \mathbb P^1(\mathbb C) </math> is a rational function with at most three critical values; we may assume these values are <math> \{ 0, \, 1, \, \infty \}. </math> A Dessin d'Enfant is a planar bipartite graph obtained by considering the preimage of a path between two of these critical values, usually taken to be the line segment from 0 to 1. Such graphs can be drawn on the sphere by composing with stereographic projection: <math> \beta^{-1} \bigl( [0,1] \bigr) \subseteq \mathbb P^1(\mathbb C) \simeq S^2(\mathbb R). </math> Replacing <math> \mathbb P^1 </math> with an elliptic curve <math>E </math>, there is a similar definition of a Bely&#301; map <math> \beta: E(\mathbb C) \to \mathbb P^1(\mathbb C). </math> Since <math> E(\mathbb C) \simeq \mathbb T^2(\mathbb R) </math> is a torus, we call <math> (E, \beta) </math> a toroidal Bely&#301; pair. The corresponding Dessin d'Enfant can be drawn on the torus by composing with an elliptic logarithm: <math> \beta^{-1} \bigl( [0,1] \bigr) \subseteq E(\mathbb C) \simeq \mathbb T^2(\mathbb R). </math><br />
<br />
This project seeks to create a database of such Bely&#301; pairs, their corresponding Dessins d'Enfant, and their monodromy groups. For each positive integer <math> N </math>, there are only finitely many toroidal Bely&#301; pairs <math> (E, \beta) </math> with <math> \deg \, \beta = N. </math> Using the Hurwitz Genus formula, we can begin this database by considering all possible degree sequences <math> \mathcal D </math> on the ramification indices as multisets on three partitions of N. For each degree sequence, we compute all possible monodromy groups <math> G = \text{im} \, \bigl[ \pi_1 \bigl( \mathbb P^1(\mathbb C) - \{ 0, \, 1, \, \infty \} \bigr) \to S_N \bigr]; </math> they are the ``Galois closure'' of the group of automorphisms of the graph. Finally, for each possible monodromy group, we compute explicit formulas for Bely&#301; maps <math> \beta: E(\mathbb C) \to \mathbb P^1(\mathbb C) </math> associated to some elliptic curve <math> E: \ y^2 = x^3 + A \, x + B. </math> We will discuss some of the challenges of determining the structure of these groups, and present visualizations of group actions on the torus. <br />
<br />
This work is part of PRiME (Purdue Research in Mathematics Experience) with Chineze Christopher, Robert Dicks, Gina Ferolito, Joseph Sauder, and Danika Van Niel with assistance by Edray Goins and Abhishek Parab.<br />
<br />
===April 13, Jill Pipher, Brown University===<br />
<br />
Title: Mathematical ideas in cryptography<br />
<br />
Abstract: This talk does not assume prior knowledge of public key crypto (PKC). I'll talk about the history of the subject and some current areas of research,<br />
including homomorphic encryption.<br />
<br />
===April 16, Christine Berkesch Zamaere (University of Minnesota)===<br />
Title: Free complexes on smooth toric varieties<br />
<br />
Abstract: Free resolutions have been a key part of using homological algebra to compute and characterize geometric invariants over projective space. Over more general smooth toric varieties, this is not the case. We will discuss the another family of complexes, called virtual resolutions, which appear to play the role of free resolutions in this setting. This is joint work with Daniel Erman and Gregory G. Smith.<br />
<br />
<br />
===April 25, Hitoshi Ishii (Tsuda University)===<br />
Title: Asymptotic problems for Hamilton-Jacobi equations and weak KAM theory<br />
<br />
Abstract: In the lecture, I discuss two asymptotic problems related to Hamilton-Jacobi equations. One concerns the long-time behavior of solutions of time evolutionary Hamilton-Jacobi equations and the other is the so-called vanishing discount problem for stationary Hamilton-Jacobi equations. The last two decades have seen a fundamental importance of weak KAM theory in the asymptotic analysis of Hamilton-Jacobi equations. I explain briefly the Aubry sets and Mather measures from weak KAM theory and their use in the analysis of the two asymptotic problems above.<br />
<br />
===May 1 and 2, Andre Neves (University of Chicago and Imperial College London)===<br />
Title: Wow, so many minimal surfaces!<br />
<br />
Abstract: Minimal surfaces are ubiquitous in geometry and applied science but their existence theory is rather mysterious. For instance, Yau in 1982 conjectured that any 3-manifold admits infinitely many closed minimal surfaces but the best one knows is the existence of at least three.<br />
<br />
After a brief historical account, I will talk about my ongoing work with Marques and the progress we made on this question jointly with Irie and Song: we showed that for generic metrics, minimal hypersurfaces are dense and equidistributed. In particular, this settles Yau’s conjecture for generic metrics.<br />
<br />
The first talk will be more general and the second talk will contain proofs of the denseness and equidistribution results. This part is joint work with Irie, Marques, and Song.<br />
<br />
== Future Colloquia ==<br />
[[Colloquia/Blank|Fall 2018]]<br />
<br />
== Past Colloquia ==<br />
<br />
[[Colloquia/Blank|Blank]]<br />
<br />
[[Colloquia/Fall2017|Fall 2017]]<br />
<br />
[[Colloquia/Spring2017|Spring 2017]]<br />
<br />
[[Archived Fall 2016 Colloquia|Fall 2016]]<br />
<br />
[[Colloquia/Spring2016|Spring 2016]]<br />
<br />
[[Colloquia/Fall2015|Fall 2015]]<br />
<br />
[[Colloquia/Spring2014|Spring 2015]]<br />
<br />
[[Colloquia/Fall2014|Fall 2014]]<br />
<br />
[[Colloquia/Spring2014|Spring 2014]]<br />
<br />
[[Colloquia/Fall2013|Fall 2013]]<br />
<br />
[[Colloquia 2012-2013|Spring 2013]]<br />
<br />
[[Colloquia 2012-2013#Fall 2012|Fall 2012]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Algebra_and_Algebraic_Geometry_Seminar_Spring_2018&diff=15350Algebra and Algebraic Geometry Seminar Spring 20182018-04-06T13:59:11Z<p>Rdavis: </p>
<hr />
<div>The seminar meets on Fridays at 2:25 pm in room B113.<br />
<br />
Here is the schedule for [[Algebraic Geometry Seminar Spring 2017 | the previous semester]].<br />
<!--, [[Algebraic Geometry Seminar Spring 2018 | the next semester]], and for [[Algebraic Geometry Seminar | this semester]]. --><br />
<br />
==Algebra and Algebraic Geometry Mailing List==<br />
<br />
<br />
*Please join the [https://admin.lists.wisc.edu/index.php?p=11&l=ags AGS Mailing List] to hear about upcoming seminars, lunches, and other algebraic geometry events in the department (it is possible you must be on a math department computer to use this link).<br />
<br />
== Spring 2018 Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s) <br />
<br />
|-<br />
|January 26<br />
|[http://homepages.math.uic.edu/~tmoulinos/ Tasos Moulinos (UIC)] <br />
|[[#Tasos Moulinos|Derived Azumaya Algebras and Twisted K-theory]]<br />
|Michael<br />
|-<br />
|February 2<br />
|Daniel Erman (Wisconsin) <br />
|[[#Daniel Erman|TBA]]<br />
|Local<br />
|-<br />
|'''February 8''' 2:30-3:30 in VV B113<br />
|[http://www.mathematics.pitt.edu/person/roman-fedorov/ Roman Fedorov (University of Pittsburgh)]<br />
|[[#Roman Fedorov|A conjecture of Grothendieck and Serre on principal bundles in mixed characteristic]]<br />
|Dima<br />
|-<br />
|February 9<br />
|Juliette Bruce (Wisconsin) <br />
|[[#Juliette Bruce|Asymptotic Syzygies in the Semi-Ample Setting ]]<br />
|Local<br />
|-<br />
|February 16<br />
|[http://www.math.wisc.edu/~andreic/ Andrei Caldararu (Wisconsin)]<br />
|[[#Andrei Caldararu|Computing a categorical Gromov-Witten invariant]]<br />
|Local<br />
|-<br />
|February 23<br />
|Aron Heleodoro (Northwestern) <br />
|[[#Aron Heleodoro|Normally ordered tensor product of Tate objects and decomposition of higher adeles]]<br />
|Dima<br />
|-<br />
|March 2<br />
|Moisés Herradón Cueto (Wisconsin)<br />
|[[#Moisés Herradón Cueto|Local type of difference equations]]<br />
|Local<br />
|-<br />
|March 9<br />
|Eva Elduque (Wisconsin)<br />
|[[#Eva Elduque|On the signed Euler characteristic property for subvarieties of Abelian varieties]]<br />
|Local<br />
|-<br />
|March 16<br />
|[https://math.berkeley.edu/~chenhi/ Harrison Chen (Berkeley)]<br />
|[[#Harrison Chen|Equivariant localization for periodic cyclic homology and derived loop spaces]]<br />
|Andrei<br />
|-<br />
|March 23<br />
|[http://www-personal.umich.edu/~ptoste/ Phil Tosteson (Michigan)]<br />
|[[#Phil Tosteson|Stability in the homology of Deligne-Mumford compactifications]]<br />
|Steven<br />
|-<br />
|-<br />
|April 6<br />
|[http://www-personal.umich.edu/~weiho/ Wei Ho (Michigan)]<br />
|Noncommutative Galois closures and moduli problems<br />
|Daniel/Wanlin<br />
|-<br />
|-<br />
|April 13<br />
|[https://sites.google.com/site/dcorey2814/ Daniel Corey (Yale)]<br />
|[#Coery|Initial degenerations of Grassmannians]<br />
|Daniel<br />
|-<br />
|April 20<br />
|Alena Pirutka (NYU)<br />
|[[#Alena Pirutka|TBA]]<br />
|Jordan<br />
|-<br />
|April 27<br />
|Alexander Yom Din (Caltech) <br />
|[[#Alexander Yom Din|Drinfeld-Gaitsgory functor and contragradient duality for (g,K)-modules]]<br />
|Dima<br />
|-<br />
|May 4<br />
|John Lesieutre (UIC) <br />
|[[#John Lesieutre|TBA]]<br />
|Daniel<br />
|}<br />
<br />
== Abstracts ==<br />
<br />
===Tasos Moulinos===<br />
<br />
'''Derived Azumaya Algebras and Twisted K-theory'''<br />
<br />
Topological K-theory of dg-categories is a localizing invariant of dg-categories over <math> \mathbb{C} </math><br />
taking values in the <math> \infty </math>-category of <math> KU </math>-modules. In this talk I describe a relative version<br />
of this construction; namely for <math>X</math> a quasi-compact, quasi-separated <math> \mathbb{C} </math>-scheme I construct a<br />
functor valued in the <math> \infty </math>-category of sheaves of spectra on <math> X(\mathbb{C}) </math>, the complex points of <math>X</math>. For inputs<br />
of the form <math>\operatorname{Perf}(X, A)</math> where <math>A</math> is an Azumaya algebra over <math>X</math>, I characterize the values<br />
of this functor in terms of the twisted topological K-theory of <math> X(\mathbb{C}) </math>. From this I deduce<br />
a certain decomposition, for <math> X </math> a finite CW-complex equipped with a bundle <math> P </math> of projective<br />
spaces over <math> X </math>, of <math> KU(P) </math> in terms of the twisted topological K-theory of <math> X </math> ; this is<br />
a topological analogue of a result of Quillen’s on the algebraic K-theory of Severi-Brauer<br />
schemes.<br />
<br />
===Roman Fedorov===<br />
<br />
'''A conjecture of Grothendieck and Serre on principal bundles in mixed<br />
characteristic'''<br />
<br />
Let G be a reductive group scheme over a regular local ring R. An old<br />
conjecture of Grothendieck and Serre predicts that such a principal<br />
bundle is trivial, if it is trivial over the fraction field of R. The<br />
conjecture has recently been proved in the "geometric" case, that is,<br />
when R contains a field. In the remaining case, the difficulty comes<br />
from the fact, that the situation is more rigid, so that a certain<br />
general position argument does not go through. I will discuss this<br />
difficulty and a way to circumvent it to obtain some partial results.<br />
<br />
===Juliette Bruce===<br />
<br />
'''Asymptotic Syzygies in the Semi-Ample Setting'''<br />
<br />
In recent years numerous conjectures have been made describing the asymptotic Betti numbers of a projective variety as the embedding line bundle becomes more ample. I will discuss recent work attempting to generalize these conjectures to the case when the embedding line bundle becomes more semi-ample. (Recall a line bundle is semi-ample if a sufficiently large multiple is base point free.) In particular, I will discuss how the monomial methods of Ein, Erman, and Lazarsfeld used to prove non-vanishing results on projective space can be extended to prove non-vanishing results for products of projective space.<br />
<br />
===Andrei Caldararu===<br />
<br />
'''Computing a categorical Gromov-Witten invariant'''<br />
<br />
In his 2005 paper "The Gromov-Witten potential associated to a TCFT" Kevin Costello described a procedure for recovering an analogue of the Gromov-Witten potential directly out of a cyclic A-inifinity algebra or category. Applying his construction to the derived category of sheaves of a complex projective variety provides a definition of higher genus B-model Gromov-Witten invariants, independent of the BCOV formalism. This has several advantages. Due to the categorical invariance of these invariants, categorical mirror symmetry automatically implies classical mirror symmetry to all genera. Also, the construction can be applied to other categories like categories of matrix factorization, giving a direct definition of FJRW invariants, for example.<br />
<br />
In my talk I shall describe the details of the computation (joint with Junwu Tu) of the invariant, at g=1, n=1, for elliptic curves. The result agrees with the predictions of mirror symmetry, matching classical calculations of Dijkgraaf. It is the first non-trivial computation of a categorical Gromov-Witten invariant.<br />
<br />
===Aron Heleodoro===<br />
<br />
'''Normally ordered tensor product of Tate objects and decomposition of higher adeles'''<br />
<br />
In this talk I will introduce the different tensor products that exist on Tate objects over vector spaces (or more generally coherent sheaves on a given scheme). As an application, I will explain how these can be used to describe higher adeles on an n-dimensional smooth scheme. Both Tate objects and higher adeles would be introduced in the talk. (This is based on joint work with Braunling, Groechenig and Wolfson.)<br />
<br />
===Moisés Herradón Cueto===<br />
<br />
'''Local type of difference equations'''<br />
<br />
The theory of algebraic differential equations on the affine line is very well-understood. In particular, there is a well-defined notion of restricting a D-module to a formal neighborhood of a point, and these restrictions are completely described by two vector spaces, called vanishing cycles and nearby cycles, and some maps between them. We give an analogous notion of "restriction to a formal disk" for difference equations that satisfies several desirable properties: first of all, a difference module can be recovered uniquely from its restriction to the complement of a point and its restriction to a formal disk around this point. Secondly, it gives rise to a local Mellin transform, which relates vanishing cycles of a difference module to nearby cycles of its Mellin transform. Since the Mellin transform of a difference module is a D-module, the Mellin transform brings us back to the familiar world of D-modules.<br />
<br />
===Eva Elduque===<br />
<br />
'''On the signed Euler characteristic property for subvarieties of Abelian varieties'''<br />
<br />
Franecki and Kapranov proved that the Euler characteristic of a perverse sheaf on a semi-abelian variety is non-negative. This result has several purely topological consequences regarding the sign of the (topological and intersection homology) Euler characteristic of a subvariety of an abelian variety, and it is natural to attempt to justify them by more elementary methods. In this talk, we'll explore the geometric tools used recently in the proof of the signed Euler<br />
characteristic property. Joint work with Christian Geske and Laurentiu Maxim.<br />
<br />
===Harrison Chen===<br />
<br />
'''Equivariant localization for periodic cyclic homology and derived loop spaces'''<br />
<br />
There is a close relationship between derived loop spaces, a geometric object, and (periodic) cyclic homology, a categorical invariant. In this talk we will discuss this relationship and how it leads to an equivariant localization result, which has an intuitive interpretation using the language of derived loop spaces. We discuss ongoing generalizations and potential applications in computing the periodic cyclic homology of categories of equivariant (coherent) sheaves on algebraic varieties.<br />
<br />
===Phil Tosteson===<br />
<br />
'''Stability in the homology of Deligne-Mumford compactifications'''<br />
<br />
The space <math>\bar M_{g,n}</math> is a compactification of the moduli space algebraic curves with marked points, obtained by allowing smooth curves to degenerate to nodal ones. We will talk about how the asymptotic behavior of its homology, <math>H_i(\bar M_{g,n})</math>, for <math>n \gg 0</math> can be studied using the representation theory of the category of finite sets and surjections.<br />
<br />
===Wei Ho===<br />
<br />
'''Noncommutative Galois closures and moduli problems'''<br />
<br />
In this talk, we will discuss the notion of a Galois closure for a possibly noncommutative algebra. We will explain how this problem is related to certain moduli problems involving genus one curves and torsors for Jacobians of higher genus curves. This is joint work with Matt Satriano.<br />
<br />
===Daniel Corey===<br />
<br />
''Initial degenerations of Grassmannians''<br />
<br />
Let Gr_0(d,n) denote the open subvariety of the Grassmannian Gr(d,n) consisting of d-1 dimensional subspaces of P^{n-1} meeting the toric boundary transversely. We prove that Gr_0(3,7) is schoen in the sense that all of its initial degenerations are smooth. The main technique we will use is to express the initial degenerations of Gr_0(3,7) as a inverse limit of thin Schubert cells. We use this to show that the Chow quotient of Gr(3,7) by the maximal torus H in GL(7) is the log canonical compactification of the moduli space of 7 lines in P^2 in linear general position.<br />
<br />
===Alexander Yom Din===<br />
<br />
'''Drinfeld-Gaitsgory functor and contragradient duality for (g,K)-modules'''<br />
<br />
Drinfeld suggested the definition of a certain endo-functor, called the pseudo-identity functor (or the Drinfeld-Gaitsgory functor), on the category of D-modules on an algebraic stack. We extend this definition to an arbitrary DG category, and show that if certain finiteness conditions are satisfied, this functor is the inverse of the Serre functor. We show that the pseudo-identity functor for (g,K)-modules is isomorphic to the composition of cohomological and contragredient dualities, which is parallel to an analogous assertion for p-adic groups.<br />
<br />
In this talk I will try to discuss some of these results and around them. This is joint work with Dennis Gaitsgory.</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Algebra_and_Algebraic_Geometry_Seminar_Spring_2018&diff=15349Algebra and Algebraic Geometry Seminar Spring 20182018-04-06T13:58:37Z<p>Rdavis: </p>
<hr />
<div>The seminar meets on Fridays at 2:25 pm in room B113.<br />
<br />
Here is the schedule for [[Algebraic Geometry Seminar Spring 2017 | the previous semester]].<br />
<!--, [[Algebraic Geometry Seminar Spring 2018 | the next semester]], and for [[Algebraic Geometry Seminar | this semester]]. --><br />
<br />
==Algebra and Algebraic Geometry Mailing List==<br />
<br />
<br />
*Please join the [https://admin.lists.wisc.edu/index.php?p=11&l=ags AGS Mailing List] to hear about upcoming seminars, lunches, and other algebraic geometry events in the department (it is possible you must be on a math department computer to use this link).<br />
<br />
== Spring 2018 Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s) <br />
<br />
|-<br />
|January 26<br />
|[http://homepages.math.uic.edu/~tmoulinos/ Tasos Moulinos (UIC)] <br />
|[[#Tasos Moulinos|Derived Azumaya Algebras and Twisted K-theory]]<br />
|Michael<br />
|-<br />
|February 2<br />
|Daniel Erman (Wisconsin) <br />
|[[#Daniel Erman|TBA]]<br />
|Local<br />
|-<br />
|'''February 8''' 2:30-3:30 in VV B113<br />
|[http://www.mathematics.pitt.edu/person/roman-fedorov/ Roman Fedorov (University of Pittsburgh)]<br />
|[[#Roman Fedorov|A conjecture of Grothendieck and Serre on principal bundles in mixed characteristic]]<br />
|Dima<br />
|-<br />
|February 9<br />
|Juliette Bruce (Wisconsin) <br />
|[[#Juliette Bruce|Asymptotic Syzygies in the Semi-Ample Setting ]]<br />
|Local<br />
|-<br />
|February 16<br />
|[http://www.math.wisc.edu/~andreic/ Andrei Caldararu (Wisconsin)]<br />
|[[#Andrei Caldararu|Computing a categorical Gromov-Witten invariant]]<br />
|Local<br />
|-<br />
|February 23<br />
|Aron Heleodoro (Northwestern) <br />
|[[#Aron Heleodoro|Normally ordered tensor product of Tate objects and decomposition of higher adeles]]<br />
|Dima<br />
|-<br />
|March 2<br />
|Moisés Herradón Cueto (Wisconsin)<br />
|[[#Moisés Herradón Cueto|Local type of difference equations]]<br />
|Local<br />
|-<br />
|March 9<br />
|Eva Elduque (Wisconsin)<br />
|[[#Eva Elduque|On the signed Euler characteristic property for subvarieties of Abelian varieties]]<br />
|Local<br />
|-<br />
|March 16<br />
|[https://math.berkeley.edu/~chenhi/ Harrison Chen (Berkeley)]<br />
|[[#Harrison Chen|Equivariant localization for periodic cyclic homology and derived loop spaces]]<br />
|Andrei<br />
|-<br />
|March 23<br />
|[http://www-personal.umich.edu/~ptoste/ Phil Tosteson (Michigan)]<br />
|[[#Phil Tosteson|Stability in the homology of Deligne-Mumford compactifications]]<br />
|Steven<br />
|-<br />
|-<br />
|April 6<br />
|http://www-personal.umich.edu/~weiho/ Wei Ho (Michigan)]<br />
|Noncommutative Galois closures and moduli problems<br />
|Daniel/Wanlin<br />
|-<br />
|-<br />
|April 13<br />
|[https://sites.google.com/site/dcorey2814/ Daniel Corey (Yale)]<br />
|[#Coery|Initial degenerations of Grassmannians]<br />
|Daniel<br />
|-<br />
|April 20<br />
|Alena Pirutka (NYU)<br />
|[[#Alena Pirutka|TBA]]<br />
|Jordan<br />
|-<br />
|April 27<br />
|Alexander Yom Din (Caltech) <br />
|[[#Alexander Yom Din|Drinfeld-Gaitsgory functor and contragradient duality for (g,K)-modules]]<br />
|Dima<br />
|-<br />
|May 4<br />
|John Lesieutre (UIC) <br />
|[[#John Lesieutre|TBA]]<br />
|Daniel<br />
|}<br />
<br />
== Abstracts ==<br />
<br />
===Tasos Moulinos===<br />
<br />
'''Derived Azumaya Algebras and Twisted K-theory'''<br />
<br />
Topological K-theory of dg-categories is a localizing invariant of dg-categories over <math> \mathbb{C} </math><br />
taking values in the <math> \infty </math>-category of <math> KU </math>-modules. In this talk I describe a relative version<br />
of this construction; namely for <math>X</math> a quasi-compact, quasi-separated <math> \mathbb{C} </math>-scheme I construct a<br />
functor valued in the <math> \infty </math>-category of sheaves of spectra on <math> X(\mathbb{C}) </math>, the complex points of <math>X</math>. For inputs<br />
of the form <math>\operatorname{Perf}(X, A)</math> where <math>A</math> is an Azumaya algebra over <math>X</math>, I characterize the values<br />
of this functor in terms of the twisted topological K-theory of <math> X(\mathbb{C}) </math>. From this I deduce<br />
a certain decomposition, for <math> X </math> a finite CW-complex equipped with a bundle <math> P </math> of projective<br />
spaces over <math> X </math>, of <math> KU(P) </math> in terms of the twisted topological K-theory of <math> X </math> ; this is<br />
a topological analogue of a result of Quillen’s on the algebraic K-theory of Severi-Brauer<br />
schemes.<br />
<br />
===Roman Fedorov===<br />
<br />
'''A conjecture of Grothendieck and Serre on principal bundles in mixed<br />
characteristic'''<br />
<br />
Let G be a reductive group scheme over a regular local ring R. An old<br />
conjecture of Grothendieck and Serre predicts that such a principal<br />
bundle is trivial, if it is trivial over the fraction field of R. The<br />
conjecture has recently been proved in the "geometric" case, that is,<br />
when R contains a field. In the remaining case, the difficulty comes<br />
from the fact, that the situation is more rigid, so that a certain<br />
general position argument does not go through. I will discuss this<br />
difficulty and a way to circumvent it to obtain some partial results.<br />
<br />
===Juliette Bruce===<br />
<br />
'''Asymptotic Syzygies in the Semi-Ample Setting'''<br />
<br />
In recent years numerous conjectures have been made describing the asymptotic Betti numbers of a projective variety as the embedding line bundle becomes more ample. I will discuss recent work attempting to generalize these conjectures to the case when the embedding line bundle becomes more semi-ample. (Recall a line bundle is semi-ample if a sufficiently large multiple is base point free.) In particular, I will discuss how the monomial methods of Ein, Erman, and Lazarsfeld used to prove non-vanishing results on projective space can be extended to prove non-vanishing results for products of projective space.<br />
<br />
===Andrei Caldararu===<br />
<br />
'''Computing a categorical Gromov-Witten invariant'''<br />
<br />
In his 2005 paper "The Gromov-Witten potential associated to a TCFT" Kevin Costello described a procedure for recovering an analogue of the Gromov-Witten potential directly out of a cyclic A-inifinity algebra or category. Applying his construction to the derived category of sheaves of a complex projective variety provides a definition of higher genus B-model Gromov-Witten invariants, independent of the BCOV formalism. This has several advantages. Due to the categorical invariance of these invariants, categorical mirror symmetry automatically implies classical mirror symmetry to all genera. Also, the construction can be applied to other categories like categories of matrix factorization, giving a direct definition of FJRW invariants, for example.<br />
<br />
In my talk I shall describe the details of the computation (joint with Junwu Tu) of the invariant, at g=1, n=1, for elliptic curves. The result agrees with the predictions of mirror symmetry, matching classical calculations of Dijkgraaf. It is the first non-trivial computation of a categorical Gromov-Witten invariant.<br />
<br />
===Aron Heleodoro===<br />
<br />
'''Normally ordered tensor product of Tate objects and decomposition of higher adeles'''<br />
<br />
In this talk I will introduce the different tensor products that exist on Tate objects over vector spaces (or more generally coherent sheaves on a given scheme). As an application, I will explain how these can be used to describe higher adeles on an n-dimensional smooth scheme. Both Tate objects and higher adeles would be introduced in the talk. (This is based on joint work with Braunling, Groechenig and Wolfson.)<br />
<br />
===Moisés Herradón Cueto===<br />
<br />
'''Local type of difference equations'''<br />
<br />
The theory of algebraic differential equations on the affine line is very well-understood. In particular, there is a well-defined notion of restricting a D-module to a formal neighborhood of a point, and these restrictions are completely described by two vector spaces, called vanishing cycles and nearby cycles, and some maps between them. We give an analogous notion of "restriction to a formal disk" for difference equations that satisfies several desirable properties: first of all, a difference module can be recovered uniquely from its restriction to the complement of a point and its restriction to a formal disk around this point. Secondly, it gives rise to a local Mellin transform, which relates vanishing cycles of a difference module to nearby cycles of its Mellin transform. Since the Mellin transform of a difference module is a D-module, the Mellin transform brings us back to the familiar world of D-modules.<br />
<br />
===Eva Elduque===<br />
<br />
'''On the signed Euler characteristic property for subvarieties of Abelian varieties'''<br />
<br />
Franecki and Kapranov proved that the Euler characteristic of a perverse sheaf on a semi-abelian variety is non-negative. This result has several purely topological consequences regarding the sign of the (topological and intersection homology) Euler characteristic of a subvariety of an abelian variety, and it is natural to attempt to justify them by more elementary methods. In this talk, we'll explore the geometric tools used recently in the proof of the signed Euler<br />
characteristic property. Joint work with Christian Geske and Laurentiu Maxim.<br />
<br />
===Harrison Chen===<br />
<br />
'''Equivariant localization for periodic cyclic homology and derived loop spaces'''<br />
<br />
There is a close relationship between derived loop spaces, a geometric object, and (periodic) cyclic homology, a categorical invariant. In this talk we will discuss this relationship and how it leads to an equivariant localization result, which has an intuitive interpretation using the language of derived loop spaces. We discuss ongoing generalizations and potential applications in computing the periodic cyclic homology of categories of equivariant (coherent) sheaves on algebraic varieties.<br />
<br />
===Phil Tosteson===<br />
<br />
'''Stability in the homology of Deligne-Mumford compactifications'''<br />
<br />
The space <math>\bar M_{g,n}</math> is a compactification of the moduli space algebraic curves with marked points, obtained by allowing smooth curves to degenerate to nodal ones. We will talk about how the asymptotic behavior of its homology, <math>H_i(\bar M_{g,n})</math>, for <math>n \gg 0</math> can be studied using the representation theory of the category of finite sets and surjections.<br />
<br />
===Wei Ho===<br />
<br />
'''Noncommutative Galois closures and moduli problems'''<br />
<br />
In this talk, we will discuss the notion of a Galois closure for a possibly noncommutative algebra. We will explain how this problem is related to certain moduli problems involving genus one curves and torsors for Jacobians of higher genus curves. This is joint work with Matt Satriano.<br />
<br />
===Daniel Corey===<br />
<br />
''Initial degenerations of Grassmannians''<br />
<br />
Let Gr_0(d,n) denote the open subvariety of the Grassmannian Gr(d,n) consisting of d-1 dimensional subspaces of P^{n-1} meeting the toric boundary transversely. We prove that Gr_0(3,7) is schoen in the sense that all of its initial degenerations are smooth. The main technique we will use is to express the initial degenerations of Gr_0(3,7) as a inverse limit of thin Schubert cells. We use this to show that the Chow quotient of Gr(3,7) by the maximal torus H in GL(7) is the log canonical compactification of the moduli space of 7 lines in P^2 in linear general position.<br />
<br />
===Alexander Yom Din===<br />
<br />
'''Drinfeld-Gaitsgory functor and contragradient duality for (g,K)-modules'''<br />
<br />
Drinfeld suggested the definition of a certain endo-functor, called the pseudo-identity functor (or the Drinfeld-Gaitsgory functor), on the category of D-modules on an algebraic stack. We extend this definition to an arbitrary DG category, and show that if certain finiteness conditions are satisfied, this functor is the inverse of the Serre functor. We show that the pseudo-identity functor for (g,K)-modules is isomorphic to the composition of cohomological and contragredient dualities, which is parallel to an analogous assertion for p-adic groups.<br />
<br />
In this talk I will try to discuss some of these results and around them. This is joint work with Dennis Gaitsgory.</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Algebra_and_Algebraic_Geometry_Seminar_Spring_2018&diff=15348Algebra and Algebraic Geometry Seminar Spring 20182018-04-06T13:56:48Z<p>Rdavis: </p>
<hr />
<div>The seminar meets on Fridays at 2:25 pm in room B113.<br />
<br />
Here is the schedule for [[Algebraic Geometry Seminar Spring 2017 | the previous semester]].<br />
<!--, [[Algebraic Geometry Seminar Spring 2018 | the next semester]], and for [[Algebraic Geometry Seminar | this semester]]. --><br />
<br />
==Algebra and Algebraic Geometry Mailing List==<br />
<br />
<br />
*Please join the [https://admin.lists.wisc.edu/index.php?p=11&l=ags AGS Mailing List] to hear about upcoming seminars, lunches, and other algebraic geometry events in the department (it is possible you must be on a math department computer to use this link).<br />
<br />
== Spring 2018 Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s) <br />
<br />
|-<br />
|January 26<br />
|[http://homepages.math.uic.edu/~tmoulinos/ Tasos Moulinos (UIC)] <br />
|[[#Tasos Moulinos|Derived Azumaya Algebras and Twisted K-theory]]<br />
|Michael<br />
|-<br />
|February 2<br />
|Daniel Erman (Wisconsin) <br />
|[[#Daniel Erman|TBA]]<br />
|Local<br />
|-<br />
|'''February 8''' 2:30-3:30 in VV B113<br />
|[http://www.mathematics.pitt.edu/person/roman-fedorov/ Roman Fedorov (University of Pittsburgh)]<br />
|[[#Roman Fedorov|A conjecture of Grothendieck and Serre on principal bundles in mixed characteristic]]<br />
|Dima<br />
|-<br />
|February 9<br />
|Juliette Bruce (Wisconsin) <br />
|[[#Juliette Bruce|Asymptotic Syzygies in the Semi-Ample Setting ]]<br />
|Local<br />
|-<br />
|February 16<br />
|[http://www.math.wisc.edu/~andreic/ Andrei Caldararu (Wisconsin)]<br />
|[[#Andrei Caldararu|Computing a categorical Gromov-Witten invariant]]<br />
|Local<br />
|-<br />
|February 23<br />
|Aron Heleodoro (Northwestern) <br />
|[[#Aron Heleodoro|Normally ordered tensor product of Tate objects and decomposition of higher adeles]]<br />
|Dima<br />
|-<br />
|March 2<br />
|Moisés Herradón Cueto (Wisconsin)<br />
|[[#Moisés Herradón Cueto|Local type of difference equations]]<br />
|Local<br />
|-<br />
|March 9<br />
|Eva Elduque (Wisconsin)<br />
|[[#Eva Elduque|On the signed Euler characteristic property for subvarieties of Abelian varieties]]<br />
|Local<br />
|-<br />
|March 16<br />
|[https://math.berkeley.edu/~chenhi/ Harrison Chen (Berkeley)]<br />
|[[#Harrison Chen|Equivariant localization for periodic cyclic homology and derived loop spaces]]<br />
|Andrei<br />
|-<br />
|March 23<br />
|[http://www-personal.umich.edu/~ptoste/ Phil Tosteson (Michigan)]<br />
|[[#Phil Tosteson|Stability in the homology of Deligne-Mumford compactifications]]<br />
|Steven<br />
|-<br />
|-<br />
|April 6<br />
|Wei Ho<br />
|Noncommutative Galois closures and moduli problems<br />
|Daniel/Wanlin<br />
|-<br />
|-<br />
|April 13<br />
|[https://sites.google.com/site/dcorey2814/ Daniel Corey (Yale)]<br />
|[#Coery|Initial degenerations of Grassmannians]<br />
|Daniel<br />
|-<br />
|April 20<br />
|Alena Pirutka (NYU)<br />
|[[#Alena Pirutka|TBA]]<br />
|Jordan<br />
|-<br />
|April 27<br />
|Alexander Yom Din (Caltech) <br />
|[[#Alexander Yom Din|Drinfeld-Gaitsgory functor and contragradient duality for (g,K)-modules]]<br />
|Dima<br />
|-<br />
|May 4<br />
|John Lesieutre (UIC) <br />
|[[#John Lesieutre|TBA]]<br />
|Daniel<br />
|}<br />
<br />
== Abstracts ==<br />
<br />
===Tasos Moulinos===<br />
<br />
'''Derived Azumaya Algebras and Twisted K-theory'''<br />
<br />
Topological K-theory of dg-categories is a localizing invariant of dg-categories over <math> \mathbb{C} </math><br />
taking values in the <math> \infty </math>-category of <math> KU </math>-modules. In this talk I describe a relative version<br />
of this construction; namely for <math>X</math> a quasi-compact, quasi-separated <math> \mathbb{C} </math>-scheme I construct a<br />
functor valued in the <math> \infty </math>-category of sheaves of spectra on <math> X(\mathbb{C}) </math>, the complex points of <math>X</math>. For inputs<br />
of the form <math>\operatorname{Perf}(X, A)</math> where <math>A</math> is an Azumaya algebra over <math>X</math>, I characterize the values<br />
of this functor in terms of the twisted topological K-theory of <math> X(\mathbb{C}) </math>. From this I deduce<br />
a certain decomposition, for <math> X </math> a finite CW-complex equipped with a bundle <math> P </math> of projective<br />
spaces over <math> X </math>, of <math> KU(P) </math> in terms of the twisted topological K-theory of <math> X </math> ; this is<br />
a topological analogue of a result of Quillen’s on the algebraic K-theory of Severi-Brauer<br />
schemes.<br />
<br />
===Roman Fedorov===<br />
<br />
'''A conjecture of Grothendieck and Serre on principal bundles in mixed<br />
characteristic'''<br />
<br />
Let G be a reductive group scheme over a regular local ring R. An old<br />
conjecture of Grothendieck and Serre predicts that such a principal<br />
bundle is trivial, if it is trivial over the fraction field of R. The<br />
conjecture has recently been proved in the "geometric" case, that is,<br />
when R contains a field. In the remaining case, the difficulty comes<br />
from the fact, that the situation is more rigid, so that a certain<br />
general position argument does not go through. I will discuss this<br />
difficulty and a way to circumvent it to obtain some partial results.<br />
<br />
===Juliette Bruce===<br />
<br />
'''Asymptotic Syzygies in the Semi-Ample Setting'''<br />
<br />
In recent years numerous conjectures have been made describing the asymptotic Betti numbers of a projective variety as the embedding line bundle becomes more ample. I will discuss recent work attempting to generalize these conjectures to the case when the embedding line bundle becomes more semi-ample. (Recall a line bundle is semi-ample if a sufficiently large multiple is base point free.) In particular, I will discuss how the monomial methods of Ein, Erman, and Lazarsfeld used to prove non-vanishing results on projective space can be extended to prove non-vanishing results for products of projective space.<br />
<br />
===Andrei Caldararu===<br />
<br />
'''Computing a categorical Gromov-Witten invariant'''<br />
<br />
In his 2005 paper "The Gromov-Witten potential associated to a TCFT" Kevin Costello described a procedure for recovering an analogue of the Gromov-Witten potential directly out of a cyclic A-inifinity algebra or category. Applying his construction to the derived category of sheaves of a complex projective variety provides a definition of higher genus B-model Gromov-Witten invariants, independent of the BCOV formalism. This has several advantages. Due to the categorical invariance of these invariants, categorical mirror symmetry automatically implies classical mirror symmetry to all genera. Also, the construction can be applied to other categories like categories of matrix factorization, giving a direct definition of FJRW invariants, for example.<br />
<br />
In my talk I shall describe the details of the computation (joint with Junwu Tu) of the invariant, at g=1, n=1, for elliptic curves. The result agrees with the predictions of mirror symmetry, matching classical calculations of Dijkgraaf. It is the first non-trivial computation of a categorical Gromov-Witten invariant.<br />
<br />
===Aron Heleodoro===<br />
<br />
'''Normally ordered tensor product of Tate objects and decomposition of higher adeles'''<br />
<br />
In this talk I will introduce the different tensor products that exist on Tate objects over vector spaces (or more generally coherent sheaves on a given scheme). As an application, I will explain how these can be used to describe higher adeles on an n-dimensional smooth scheme. Both Tate objects and higher adeles would be introduced in the talk. (This is based on joint work with Braunling, Groechenig and Wolfson.)<br />
<br />
===Moisés Herradón Cueto===<br />
<br />
'''Local type of difference equations'''<br />
<br />
The theory of algebraic differential equations on the affine line is very well-understood. In particular, there is a well-defined notion of restricting a D-module to a formal neighborhood of a point, and these restrictions are completely described by two vector spaces, called vanishing cycles and nearby cycles, and some maps between them. We give an analogous notion of "restriction to a formal disk" for difference equations that satisfies several desirable properties: first of all, a difference module can be recovered uniquely from its restriction to the complement of a point and its restriction to a formal disk around this point. Secondly, it gives rise to a local Mellin transform, which relates vanishing cycles of a difference module to nearby cycles of its Mellin transform. Since the Mellin transform of a difference module is a D-module, the Mellin transform brings us back to the familiar world of D-modules.<br />
<br />
===Eva Elduque===<br />
<br />
'''On the signed Euler characteristic property for subvarieties of Abelian varieties'''<br />
<br />
Franecki and Kapranov proved that the Euler characteristic of a perverse sheaf on a semi-abelian variety is non-negative. This result has several purely topological consequences regarding the sign of the (topological and intersection homology) Euler characteristic of a subvariety of an abelian variety, and it is natural to attempt to justify them by more elementary methods. In this talk, we'll explore the geometric tools used recently in the proof of the signed Euler<br />
characteristic property. Joint work with Christian Geske and Laurentiu Maxim.<br />
<br />
===Harrison Chen===<br />
<br />
'''Equivariant localization for periodic cyclic homology and derived loop spaces'''<br />
<br />
There is a close relationship between derived loop spaces, a geometric object, and (periodic) cyclic homology, a categorical invariant. In this talk we will discuss this relationship and how it leads to an equivariant localization result, which has an intuitive interpretation using the language of derived loop spaces. We discuss ongoing generalizations and potential applications in computing the periodic cyclic homology of categories of equivariant (coherent) sheaves on algebraic varieties.<br />
<br />
===Phil Tosteson===<br />
<br />
'''Stability in the homology of Deligne-Mumford compactifications'''<br />
<br />
The space <math>\bar M_{g,n}</math> is a compactification of the moduli space algebraic curves with marked points, obtained by allowing smooth curves to degenerate to nodal ones. We will talk about how the asymptotic behavior of its homology, <math>H_i(\bar M_{g,n})</math>, for <math>n \gg 0</math> can be studied using the representation theory of the category of finite sets and surjections.<br />
<br />
===Wei Ho===<br />
<br />
'''Noncommutative Galois closures and moduli problems'''<br />
<br />
In this talk, we will discuss the notion of a Galois closure for a possibly noncommutative algebra. We will explain how this problem is related to certain moduli problems involving genus one curves and torsors for Jacobians of higher genus curves. This is joint work with Matt Satriano.<br />
<br />
===Daniel Corey===<br />
<br />
''Initial degenerations of Grassmannians''<br />
<br />
Let Gr_0(d,n) denote the open subvariety of the Grassmannian Gr(d,n) consisting of d-1 dimensional subspaces of P^{n-1} meeting the toric boundary transversely. We prove that Gr_0(3,7) is schoen in the sense that all of its initial degenerations are smooth. The main technique we will use is to express the initial degenerations of Gr_0(3,7) as a inverse limit of thin Schubert cells. We use this to show that the Chow quotient of Gr(3,7) by the maximal torus H in GL(7) is the log canonical compactification of the moduli space of 7 lines in P^2 in linear general position.<br />
<br />
===Alexander Yom Din===<br />
<br />
'''Drinfeld-Gaitsgory functor and contragradient duality for (g,K)-modules'''<br />
<br />
Drinfeld suggested the definition of a certain endo-functor, called the pseudo-identity functor (or the Drinfeld-Gaitsgory functor), on the category of D-modules on an algebraic stack. We extend this definition to an arbitrary DG category, and show that if certain finiteness conditions are satisfied, this functor is the inverse of the Serre functor. We show that the pseudo-identity functor for (g,K)-modules is isomorphic to the composition of cohomological and contragredient dualities, which is parallel to an analogous assertion for p-adic groups.<br />
<br />
In this talk I will try to discuss some of these results and around them. This is joint work with Dennis Gaitsgory.</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Algebra_and_Algebraic_Geometry_Seminar_Spring_2018&diff=15347Algebra and Algebraic Geometry Seminar Spring 20182018-04-06T13:54:04Z<p>Rdavis: </p>
<hr />
<div>The seminar meets on Fridays at 2:25 pm in room B113.<br />
<br />
Here is the schedule for [[Algebraic Geometry Seminar Spring 2017 | the previous semester]].<br />
<!--, [[Algebraic Geometry Seminar Spring 2018 | the next semester]], and for [[Algebraic Geometry Seminar | this semester]]. --><br />
<br />
==Algebra and Algebraic Geometry Mailing List==<br />
<br />
<br />
*Please join the [https://admin.lists.wisc.edu/index.php?p=11&l=ags AGS Mailing List] to hear about upcoming seminars, lunches, and other algebraic geometry events in the department (it is possible you must be on a math department computer to use this link).<br />
<br />
== Spring 2018 Schedule ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s) <br />
<br />
|-<br />
|January 26<br />
|[http://homepages.math.uic.edu/~tmoulinos/ Tasos Moulinos (UIC)] <br />
|[[#Tasos Moulinos|Derived Azumaya Algebras and Twisted K-theory]]<br />
|Michael<br />
|-<br />
|February 2<br />
|Daniel Erman (Wisconsin) <br />
|[[#Daniel Erman|TBA]]<br />
|Local<br />
|-<br />
|'''February 8''' 2:30-3:30 in VV B113<br />
|[http://www.mathematics.pitt.edu/person/roman-fedorov/ Roman Fedorov (University of Pittsburgh)]<br />
|[[#Roman Fedorov|A conjecture of Grothendieck and Serre on principal bundles in mixed characteristic]]<br />
|Dima<br />
|-<br />
|February 9<br />
|Juliette Bruce (Wisconsin) <br />
|[[#Juliette Bruce|Asymptotic Syzygies in the Semi-Ample Setting ]]<br />
|Local<br />
|-<br />
|February 16<br />
|[http://www.math.wisc.edu/~andreic/ Andrei Caldararu (Wisconsin)]<br />
|[[#Andrei Caldararu|Computing a categorical Gromov-Witten invariant]]<br />
|Local<br />
|-<br />
|February 23<br />
|Aron Heleodoro (Northwestern) <br />
|[[#Aron Heleodoro|Normally ordered tensor product of Tate objects and decomposition of higher adeles]]<br />
|Dima<br />
|-<br />
|March 2<br />
|Moisés Herradón Cueto (Wisconsin)<br />
|[[#Moisés Herradón Cueto|Local type of difference equations]]<br />
|Local<br />
|-<br />
|March 9<br />
|Eva Elduque (Wisconsin)<br />
|[[#Eva Elduque|On the signed Euler characteristic property for subvarieties of Abelian varieties]]<br />
|Local<br />
|-<br />
|March 16<br />
|[https://math.berkeley.edu/~chenhi/ Harrison Chen (Berkeley)]<br />
|[[#Harrison Chen|Equivariant localization for periodic cyclic homology and derived loop spaces]]<br />
|Andrei<br />
|-<br />
|March 23<br />
|[http://www-personal.umich.edu/~ptoste/ Phil Tosteson (Michigan)]<br />
|[[#Phil Tosteson|Stability in the homology of Deligne-Mumford compactifications]]<br />
|Steven<br />
|-<br />
|-<br />
|April 6<br />
|Wei Ho<br />
|Noncommutative Galois closures and moduli problems<br />
|Daniel/Wanlin<br />
|-<br />
|-<br />
|April 13<br />
|[https://sites.google.com/site/dcorey2814/ Daniel Corey (Yale)]<br />
|[#Coery|Initial degenerations of Grassmannians]<br />
|Daniel<br />
|-<br />
|April 20<br />
|Alena Pirutka (NYU)<br />
|[[#Alena Pirutka|TBA]]<br />
|Jordan<br />
|-<br />
|April 27<br />
|Alexander Yom Din (Caltech) <br />
|[[#Alexander Yom Din|Drinfeld-Gaitsgory functor and contragradient duality for (g,K)-modules]]<br />
|Dima<br />
|-<br />
|May 4<br />
|John Lesieutre (UIC) <br />
|[[#John Lesieutre|TBA]]<br />
|Daniel<br />
|}<br />
<br />
== Abstracts ==<br />
<br />
===Tasos Moulinos===<br />
<br />
'''Derived Azumaya Algebras and Twisted K-theory'''<br />
<br />
Topological K-theory of dg-categories is a localizing invariant of dg-categories over <math> \mathbb{C} </math><br />
taking values in the <math> \infty </math>-category of <math> KU </math>-modules. In this talk I describe a relative version<br />
of this construction; namely for <math>X</math> a quasi-compact, quasi-separated <math> \mathbb{C} </math>-scheme I construct a<br />
functor valued in the <math> \infty </math>-category of sheaves of spectra on <math> X(\mathbb{C}) </math>, the complex points of <math>X</math>. For inputs<br />
of the form <math>\operatorname{Perf}(X, A)</math> where <math>A</math> is an Azumaya algebra over <math>X</math>, I characterize the values<br />
of this functor in terms of the twisted topological K-theory of <math> X(\mathbb{C}) </math>. From this I deduce<br />
a certain decomposition, for <math> X </math> a finite CW-complex equipped with a bundle <math> P </math> of projective<br />
spaces over <math> X </math>, of <math> KU(P) </math> in terms of the twisted topological K-theory of <math> X </math> ; this is<br />
a topological analogue of a result of Quillen’s on the algebraic K-theory of Severi-Brauer<br />
schemes.<br />
<br />
===Roman Fedorov===<br />
<br />
'''A conjecture of Grothendieck and Serre on principal bundles in mixed<br />
characteristic'''<br />
<br />
Let G be a reductive group scheme over a regular local ring R. An old<br />
conjecture of Grothendieck and Serre predicts that such a principal<br />
bundle is trivial, if it is trivial over the fraction field of R. The<br />
conjecture has recently been proved in the "geometric" case, that is,<br />
when R contains a field. In the remaining case, the difficulty comes<br />
from the fact, that the situation is more rigid, so that a certain<br />
general position argument does not go through. I will discuss this<br />
difficulty and a way to circumvent it to obtain some partial results.<br />
<br />
===Juliette Bruce===<br />
<br />
'''Asymptotic Syzygies in the Semi-Ample Setting'''<br />
<br />
In recent years numerous conjectures have been made describing the asymptotic Betti numbers of a projective variety as the embedding line bundle becomes more ample. I will discuss recent work attempting to generalize these conjectures to the case when the embedding line bundle becomes more semi-ample. (Recall a line bundle is semi-ample if a sufficiently large multiple is base point free.) In particular, I will discuss how the monomial methods of Ein, Erman, and Lazarsfeld used to prove non-vanishing results on projective space can be extended to prove non-vanishing results for products of projective space.<br />
<br />
===Andrei Caldararu===<br />
<br />
'''Computing a categorical Gromov-Witten invariant'''<br />
<br />
In his 2005 paper "The Gromov-Witten potential associated to a TCFT" Kevin Costello described a procedure for recovering an analogue of the Gromov-Witten potential directly out of a cyclic A-inifinity algebra or category. Applying his construction to the derived category of sheaves of a complex projective variety provides a definition of higher genus B-model Gromov-Witten invariants, independent of the BCOV formalism. This has several advantages. Due to the categorical invariance of these invariants, categorical mirror symmetry automatically implies classical mirror symmetry to all genera. Also, the construction can be applied to other categories like categories of matrix factorization, giving a direct definition of FJRW invariants, for example.<br />
<br />
In my talk I shall describe the details of the computation (joint with Junwu Tu) of the invariant, at g=1, n=1, for elliptic curves. The result agrees with the predictions of mirror symmetry, matching classical calculations of Dijkgraaf. It is the first non-trivial computation of a categorical Gromov-Witten invariant.<br />
<br />
===Aron Heleodoro===<br />
<br />
'''Normally ordered tensor product of Tate objects and decomposition of higher adeles'''<br />
<br />
In this talk I will introduce the different tensor products that exist on Tate objects over vector spaces (or more generally coherent sheaves on a given scheme). As an application, I will explain how these can be used to describe higher adeles on an n-dimensional smooth scheme. Both Tate objects and higher adeles would be introduced in the talk. (This is based on joint work with Braunling, Groechenig and Wolfson.)<br />
<br />
===Moisés Herradón Cueto===<br />
<br />
'''Local type of difference equations'''<br />
<br />
The theory of algebraic differential equations on the affine line is very well-understood. In particular, there is a well-defined notion of restricting a D-module to a formal neighborhood of a point, and these restrictions are completely described by two vector spaces, called vanishing cycles and nearby cycles, and some maps between them. We give an analogous notion of "restriction to a formal disk" for difference equations that satisfies several desirable properties: first of all, a difference module can be recovered uniquely from its restriction to the complement of a point and its restriction to a formal disk around this point. Secondly, it gives rise to a local Mellin transform, which relates vanishing cycles of a difference module to nearby cycles of its Mellin transform. Since the Mellin transform of a difference module is a D-module, the Mellin transform brings us back to the familiar world of D-modules.<br />
<br />
===Eva Elduque===<br />
<br />
'''On the signed Euler characteristic property for subvarieties of Abelian varieties'''<br />
<br />
Franecki and Kapranov proved that the Euler characteristic of a perverse sheaf on a semi-abelian variety is non-negative. This result has several purely topological consequences regarding the sign of the (topological and intersection homology) Euler characteristic of a subvariety of an abelian variety, and it is natural to attempt to justify them by more elementary methods. In this talk, we'll explore the geometric tools used recently in the proof of the signed Euler<br />
characteristic property. Joint work with Christian Geske and Laurentiu Maxim.<br />
<br />
===Harrison Chen===<br />
<br />
'''Equivariant localization for periodic cyclic homology and derived loop spaces'''<br />
<br />
There is a close relationship between derived loop spaces, a geometric object, and (periodic) cyclic homology, a categorical invariant. In this talk we will discuss this relationship and how it leads to an equivariant localization result, which has an intuitive interpretation using the language of derived loop spaces. We discuss ongoing generalizations and potential applications in computing the periodic cyclic homology of categories of equivariant (coherent) sheaves on algebraic varieties.<br />
<br />
===Phil Tosteson===<br />
<br />
'''Stability in the homology of Deligne-Mumford compactifications'''<br />
<br />
The space <math>\bar M_{g,n}</math> is a compactification of the moduli space algebraic curves with marked points, obtained by allowing smooth curves to degenerate to nodal ones. We will talk about how the asymptotic behavior of its homology, <math>H_i(\bar M_{g,n})</math>, for <math>n \gg 0</math> can be studied using the representation theory of the category of finite sets and surjections.<br />
<br />
===Wei Ho===<br />
In this talk, we will discuss the notion of a Galois closure for a possibly noncommutative algebra. We will explain how this problem is related to certain moduli problems involving genus one curves and torsors for Jacobians of higher genus curves. This is joint work with Matt Satriano.<br />
<br />
===Daniel Corey===<br />
<br />
''Initial degenerations of Grassmannians''<br />
<br />
Let Gr_0(d,n) denote the open subvariety of the Grassmannian Gr(d,n) consisting of d-1 dimensional subspaces of P^{n-1} meeting the toric boundary transversely. We prove that Gr_0(3,7) is schoen in the sense that all of its initial degenerations are smooth. The main technique we will use is to express the initial degenerations of Gr_0(3,7) as a inverse limit of thin Schubert cells. We use this to show that the Chow quotient of Gr(3,7) by the maximal torus H in GL(7) is the log canonical compactification of the moduli space of 7 lines in P^2 in linear general position.<br />
<br />
===Alexander Yom Din===<br />
<br />
'''Drinfeld-Gaitsgory functor and contragradient duality for (g,K)-modules'''<br />
<br />
Drinfeld suggested the definition of a certain endo-functor, called the pseudo-identity functor (or the Drinfeld-Gaitsgory functor), on the category of D-modules on an algebraic stack. We extend this definition to an arbitrary DG category, and show that if certain finiteness conditions are satisfied, this functor is the inverse of the Serre functor. We show that the pseudo-identity functor for (g,K)-modules is isomorphic to the composition of cohomological and contragredient dualities, which is parallel to an analogous assertion for p-adic groups.<br />
<br />
In this talk I will try to discuss some of these results and around them. This is joint work with Dennis Gaitsgory.</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Colloquia/Fall18&diff=15209Colloquia/Fall182018-03-05T15:33:24Z<p>Rdavis: /* April 6 Edray Goins (Purdue) */</p>
<hr />
<div>= Mathematics Colloquium =<br />
<br />
All colloquia are on Fridays at 4:00 pm in Van Vleck B239, '''unless otherwise indicated'''.<br />
<br />
== Spring 2018 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date <br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
|-<br />
|January 29 (Monday)<br />
| [http://www.math.columbia.edu/~chaoli/ Li Chao] (Columbia)<br />
|[[#January 29 Li Chao (Columbia)| Elliptic curves and Goldfeld's conjecture ]]<br />
| Jordan Ellenberg<br />
|<br />
|-<br />
|February 2 (Room: 911)<br />
| [https://scholar.harvard.edu/tfai/home Thomas Fai] (Harvard)<br />
|[[#February 2 Thomas Fai (Harvard)| The Lubricated Immersed Boundary Method ]]<br />
| Spagnolie, Smith<br />
|<br />
|-<br />
|February 5 (Monday, Room: 911)<br />
| [http://www.ma.huji.ac.il/~alexlub/ Alex Lubotzky] (Hebrew University) <br />
|[[#February 5 Alex Lubotzky (Hebrew University)| High dimensional expanders: From Ramanujan graphs to Ramanujan complexes ]]<br />
| Ellenberg, Gurevitch<br />
|<br />
|-<br />
|February 6 (Tuesday 2 pm, Room 911)<br />
| [http://www.ma.huji.ac.il/~alexlub/ Alex Lubotzky] (Hebrew University) <br />
|[[#February 6 Alex Lubotzky (Hebrew University)| Groups' approximation, stability and high dimensional expanders ]]<br />
| Ellenberg, Gurevitch<br />
|<br />
|-<br />
|February 9<br />
| [http://www.math.cmu.edu/~wes/ Wes Pegden] (CMU)<br />
|[[#February 9 Wes Pegden (CMU)| The fractal nature of the Abelian Sandpile ]]<br />
| Roch<br />
|<br />
|-<br />
|March 2<br />
| [http://www.math.utah.edu/~bertram/ Aaron Bertram] (University of Utah)<br />
|[[#March 2 Aaron Bertram (Utah)| Stability in Algebraic Geometry ]]<br />
| Caldararu<br />
|<br />
|-<br />
| March 16<br />
|[https://math.dartmouth.edu/~annegelb/ Anne Gelb] (Dartmouth)<br />
|[[# TBA| TBA ]]<br />
| WIMAW<br />
|<br />
|-<br />
|April 4 (Wednesday)<br />
| [http://math.ucr.edu/home/baez/ John Baez] (UC Riverside)<br />
|[[# TBA| TBA ]]<br />
| Craciun<br />
|<br />
|-<br />
| April 6<br />
| [https://www.math.purdue.edu/~egoins Edray Goins] (Purdue)<br />
|[[# Edray Goins| Toroidal Bely&#301; Pairs, Toroidal Graphs, and their Monodromy Groups ]]<br />
| Melanie<br />
|<br />
|-<br />
| April 13<br />
| [https://www.math.brown.edu/~jpipher/ Jill Pipher] (Brown)<br />
|[[# TBA| TBA ]]<br />
| WIMAW<br />
|<br />
|-<br />
| April 20<br />
| Xiuxiong Chen(Stony Brook University)<br />
|[[# Xiuxiong Chen| TBA ]]<br />
| Bing Wang<br />
|<br />
|-<br />
| April 25 (Wednesday)<br />
| [http://www.f.waseda.jp/hitoshi.ishii/ Hitoshi Ishii] (Waseda University) Wasow lecture<br />
|[[# TBA| TBA ]]<br />
| Tran<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
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|-<br />
|date<br />
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|[[# TBA| TBA ]]<br />
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|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
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|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
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|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|}<br />
<br />
== Spring Abstracts ==<br />
<br />
<br />
===January 29 Li Chao (Columbia)===<br />
<br />
Title: Elliptic curves and Goldfeld's conjecture<br />
<br />
Abstract: <br />
An elliptic curve is a plane curve defined by a cubic equation. Determining whether such an equation has infinitely many rational solutions has been a central problem in number theory for centuries, which lead to the celebrated conjecture of Birch and Swinnerton-Dyer. Within a family of elliptic curves (such as the Mordell curve family y^2=x^3-d), a conjecture of Goldfeld further predicts that there should be infinitely many rational solutions exactly half of the time. We will start with a history of this problem, discuss our recent work (with D. Kriz) towards Goldfeld's conjecture and illustrate the key ideas and ingredients behind these new progresses.<br />
<br />
=== February 2 Thomas Fai (Harvard) ===<br />
<br />
Title: The Lubricated Immersed Boundary Method<br />
<br />
Abstract:<br />
Many real-world examples of fluid-structure interaction, including the transit of red blood cells through the narrow slits in the spleen, involve the near-contact of elastic structures separated by thin layers of fluid. The separation of length scales between these fine lubrication layers and the larger elastic objects poses significant computational challenges. Motivated by the challenge of resolving such multiscale problems, we introduce an immersed boundary method that uses elements of lubrication theory to resolve thin fluid layers between immersed boundaries. We apply this method to two-dimensional flows of increasing complexity, including eccentric rotating cylinders and elastic vesicles near walls in shear flow, to show its increased accuracy compared to the classical immersed boundary method. We present preliminary simulation results of cell suspensions, a problem in which near-contact occurs at multiple levels, such as cell-wall, cell-cell, and intracellular interactions, to highlight the importance of resolving thin fluid layers in order to obtain the correct overall dynamics.<br />
<br />
===February 5 Alex Lubotzky (Hebrew University)===<br />
<br />
Title: High dimensional expanders: From Ramanujan graphs to Ramanujan complexes<br />
<br />
Abstract: <br />
<br />
Expander graphs in general, and Ramanujan graphs , in particular, have played a major role in computer science in the last 5 decades and more recently also in pure math. The first explicit construction of bounded degree expanding graphs was given by Margulis in the early 70's. In mid 80' Margulis and Lubotzky-Phillips-Sarnak provided Ramanujan graphs which are optimal such expanders. <br />
<br />
In recent years a high dimensional theory of expanders is emerging. A notion of topological expanders was defined by Gromov in 2010 who proved that the complete d-dimensional simplical complexes are such. He raised the basic question of existence of such bounded degree complexes of dimension d>1. <br />
<br />
This question was answered recently affirmatively (by T. Kaufman, D. Kazdhan and A. Lubotzky for d=2 and by S. Evra and T. Kaufman for general d) by showing that the d-skeleton of (d+1)-dimensional Ramanujan complexes provide such topological expanders. We will describe these developments and the general area of high dimensional expanders. <br />
<br />
<br />
===February 6 Alex Lubotzky (Hebrew University)===<br />
<br />
Title: Groups' approximation, stability and high dimensional expanders<br />
<br />
Abstract: <br />
<br />
Several well-known open questions, such as: are all groups sofic or hyperlinear?, have a common form: can all groups be approximated by asymptotic homomorphisms into the symmetric groups Sym(n) (in the sofic case) or the unitary groups U(n) (in the hyperlinear case)? In the case of U(n), the question can be asked with respect to different metrics and norms. We answer, for the first time, one of these versions, showing that there exist fintely presented groups which are not approximated by U(n) with respect to the Frobenius (=L_2) norm.<br />
<br />
The strategy is via the notion of "stability": some higher dimensional cohomology vanishing phenomena is proven to imply stability and using high dimensional expanders, it is shown that some non-residually finite groups (central extensions of some lattices in p-adic Lie groups) are Frobenious stable and hence cannot be Frobenius approximated. <br />
<br />
All notions will be explained. Joint work with M, De Chiffre, L. Glebsky and A. Thom.<br />
<br />
===February 9 Wes Pegden (CMU)===<br />
<br />
Title: The fractal nature of the Abelian Sandpile <br />
<br />
Abstract: The Abelian Sandpile is a simple diffusion process on the integer lattice, in which configurations of chips disperse according to a simple rule: when a vertex has at least 4 chips, it can distribute one chip to each neighbor. <br />
<br />
Introduced in the statistical physics community in the 1980s, the Abelian sandpile exhibits striking fractal behavior which long resisted rigorous mathematical analysis (or even a plausible explanation). We now have a relatively robust mathematical understanding of this fractal nature of the sandpile, which involves surprising connections between integer superharmonic functions on the lattice, discrete tilings of the plane, and Apollonian circle packings. In this talk, we will survey our work in this area, and discuss avenues of current and future research.<br />
<br />
===March 2 Aaron Bertram (Utah)===<br />
<br />
Title: Stability in Algebraic Geometry<br />
<br />
Abstract: Stability was originally introduced in algebraic geometry in the context of finding a projective quotient space for the action of an algebraic group on a projective manifold. This, in turn, led in the 1960s to a notion of slope-stability for vector bundles on a Riemann surface, which was an important tool in the classification of vector bundles. In the 1990s, mirror symmetry considerations led Michael Douglas to notions of stability for "D-branes" (on a higher-dimensional manifold) that corresponded to no previously known mathematical definition. We now understand each of these notions of stability as a distinct point of a complex "stability manifold" that is an important invariant of the (derived) category of complexes of vector bundles of a projective manifold. In this talk I want to give some examples to illustrate the various stabilities, and also to describe some current work in the area.<br />
<br />
===April 6 Edray Goins (Purdue)===<br />
<br />
Title: Toroidal Bely&#301; Pairs, Toroidal Graphs, and their Monodromy Groups<br />
<br />
Abstract: A Bely&#301; map <math> \beta: \mathbb P^1(\mathbb C) \to \mathbb P^1(\mathbb C) </math> is a rational function with at most three critical values; we may assume these values are <math> \{ 0, \, 1, \, \infty \}. </math> A Dessin d'Enfant is a planar bipartite graph obtained by considering the preimage of a path between two of these critical values, usually taken to be the line segment from 0 to 1. Such graphs can be drawn on the sphere by composing with stereographic projection: <math> \beta^{-1} \bigl( [0,1] \bigr) \subseteq \mathbb P^1(\mathbb C) \simeq S^2(\mathbb R). </math> Replacing <math> \mathbb P^1 </math> with an elliptic curve <math>E </math>, there is a similar definition of a Bely&#301; map <math> \beta: E(\mathbb C) \to \mathbb P^1(\mathbb C). </math> Since <math> E(\mathbb C) \simeq \mathbb T^2(\mathbb R) </math> is a torus, we call <math> (E, \beta) </math> a toroidal Bely&#301; pair. The corresponding Dessin d'Enfant can be drawn on the torus by composing with an elliptic logarithm: <math> \beta^{-1} \bigl( [0,1] \bigr) \subseteq E(\mathbb C) \simeq \mathbb T^2(\mathbb R). </math><br />
<br />
This project seeks to create a database of such Bely&#301; pairs, their corresponding Dessins d'Enfant, and their monodromy groups. For each positive integer <math> N </math>, there are only finitely many toroidal Bely&#301; pairs <math> (E, \beta) </math> with <math> \deg \, \beta = N. </math> Using the Hurwitz Genus formula, we can begin this database by considering all possible degree sequences <math> \mathcal D </math> on the ramification indices as multisets on three partitions of N. For each degree sequence, we compute all possible monodromy groups <math> G = \text{im} \, \bigl[ \pi_1 \bigl( \mathbb P^1(\mathbb C) - \{ 0, \, 1, \, \infty \} \bigr) \to S_N \bigr]; </math> they are the ``Galois closure'' of the group of automorphisms of the graph. Finally, for each possible monodromy group, we compute explicit formulas for Bely&#301; maps <math> \beta: E(\mathbb C) \to \mathbb P^1(\mathbb C) </math> associated to some elliptic curve <math> E: \ y^2 = x^3 + A \, x + B. </math> We will discuss some of the challenges of determining the structure of these groups, and present visualizations of group actions on the torus. <br />
<br />
This work is part of PRiME (Purdue Research in Mathematics Experience) with Chineze Christopher, Robert Dicks, Gina Ferolito, Joseph Sauder, and Danika Van Niel with assistance by Edray Goins and Abhishek Parab.<br />
<br />
== Past Colloquia ==<br />
<br />
[[Colloquia/Blank|Blank Colloquia]]<br />
<br />
[[Colloquia/Fall2017|Fall 2017]]<br />
<br />
[[Colloquia/Spring2017|Spring 2017]]<br />
<br />
[[Archived Fall 2016 Colloquia|Fall 2016]]<br />
<br />
[[Colloquia/Spring2016|Spring 2016]]<br />
<br />
[[Colloquia/Fall2015|Fall 2015]]<br />
<br />
[[Colloquia/Spring2014|Spring 2015]]<br />
<br />
[[Colloquia/Fall2014|Fall 2014]]<br />
<br />
[[Colloquia/Spring2014|Spring 2014]]<br />
<br />
[[Colloquia/Fall2013|Fall 2013]]<br />
<br />
[[Colloquia 2012-2013|Spring 2013]]<br />
<br />
[[Colloquia 2012-2013#Fall 2012|Fall 2012]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Colloquia/Fall18&diff=15208Colloquia/Fall182018-03-05T15:31:21Z<p>Rdavis: </p>
<hr />
<div>= Mathematics Colloquium =<br />
<br />
All colloquia are on Fridays at 4:00 pm in Van Vleck B239, '''unless otherwise indicated'''.<br />
<br />
== Spring 2018 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date <br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
|-<br />
|January 29 (Monday)<br />
| [http://www.math.columbia.edu/~chaoli/ Li Chao] (Columbia)<br />
|[[#January 29 Li Chao (Columbia)| Elliptic curves and Goldfeld's conjecture ]]<br />
| Jordan Ellenberg<br />
|<br />
|-<br />
|February 2 (Room: 911)<br />
| [https://scholar.harvard.edu/tfai/home Thomas Fai] (Harvard)<br />
|[[#February 2 Thomas Fai (Harvard)| The Lubricated Immersed Boundary Method ]]<br />
| Spagnolie, Smith<br />
|<br />
|-<br />
|February 5 (Monday, Room: 911)<br />
| [http://www.ma.huji.ac.il/~alexlub/ Alex Lubotzky] (Hebrew University) <br />
|[[#February 5 Alex Lubotzky (Hebrew University)| High dimensional expanders: From Ramanujan graphs to Ramanujan complexes ]]<br />
| Ellenberg, Gurevitch<br />
|<br />
|-<br />
|February 6 (Tuesday 2 pm, Room 911)<br />
| [http://www.ma.huji.ac.il/~alexlub/ Alex Lubotzky] (Hebrew University) <br />
|[[#February 6 Alex Lubotzky (Hebrew University)| Groups' approximation, stability and high dimensional expanders ]]<br />
| Ellenberg, Gurevitch<br />
|<br />
|-<br />
|February 9<br />
| [http://www.math.cmu.edu/~wes/ Wes Pegden] (CMU)<br />
|[[#February 9 Wes Pegden (CMU)| The fractal nature of the Abelian Sandpile ]]<br />
| Roch<br />
|<br />
|-<br />
|March 2<br />
| [http://www.math.utah.edu/~bertram/ Aaron Bertram] (University of Utah)<br />
|[[#March 2 Aaron Bertram (Utah)| Stability in Algebraic Geometry ]]<br />
| Caldararu<br />
|<br />
|-<br />
| March 16<br />
|[https://math.dartmouth.edu/~annegelb/ Anne Gelb] (Dartmouth)<br />
|[[# TBA| TBA ]]<br />
| WIMAW<br />
|<br />
|-<br />
|April 4 (Wednesday)<br />
| [http://math.ucr.edu/home/baez/ John Baez] (UC Riverside)<br />
|[[# TBA| TBA ]]<br />
| Craciun<br />
|<br />
|-<br />
| April 6<br />
| [https://www.math.purdue.edu/~egoins Edray Goins] (Purdue)<br />
|[[# Edray Goins| Toroidal Bely&#301; Pairs, Toroidal Graphs, and their Monodromy Groups ]]<br />
| Melanie<br />
|<br />
|-<br />
| April 13<br />
| [https://www.math.brown.edu/~jpipher/ Jill Pipher] (Brown)<br />
|[[# TBA| TBA ]]<br />
| WIMAW<br />
|<br />
|-<br />
| April 20<br />
| Xiuxiong Chen(Stony Brook University)<br />
|[[# Xiuxiong Chen| TBA ]]<br />
| Bing Wang<br />
|<br />
|-<br />
| April 25 (Wednesday)<br />
| [http://www.f.waseda.jp/hitoshi.ishii/ Hitoshi Ishii] (Waseda University) Wasow lecture<br />
|[[# TBA| TBA ]]<br />
| Tran<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
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|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
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|<br />
|-<br />
|date<br />
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|[[# TBA| TBA ]]<br />
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|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
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|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|}<br />
<br />
== Spring Abstracts ==<br />
<br />
<br />
===January 29 Li Chao (Columbia)===<br />
<br />
Title: Elliptic curves and Goldfeld's conjecture<br />
<br />
Abstract: <br />
An elliptic curve is a plane curve defined by a cubic equation. Determining whether such an equation has infinitely many rational solutions has been a central problem in number theory for centuries, which lead to the celebrated conjecture of Birch and Swinnerton-Dyer. Within a family of elliptic curves (such as the Mordell curve family y^2=x^3-d), a conjecture of Goldfeld further predicts that there should be infinitely many rational solutions exactly half of the time. We will start with a history of this problem, discuss our recent work (with D. Kriz) towards Goldfeld's conjecture and illustrate the key ideas and ingredients behind these new progresses.<br />
<br />
=== February 2 Thomas Fai (Harvard) ===<br />
<br />
Title: The Lubricated Immersed Boundary Method<br />
<br />
Abstract:<br />
Many real-world examples of fluid-structure interaction, including the transit of red blood cells through the narrow slits in the spleen, involve the near-contact of elastic structures separated by thin layers of fluid. The separation of length scales between these fine lubrication layers and the larger elastic objects poses significant computational challenges. Motivated by the challenge of resolving such multiscale problems, we introduce an immersed boundary method that uses elements of lubrication theory to resolve thin fluid layers between immersed boundaries. We apply this method to two-dimensional flows of increasing complexity, including eccentric rotating cylinders and elastic vesicles near walls in shear flow, to show its increased accuracy compared to the classical immersed boundary method. We present preliminary simulation results of cell suspensions, a problem in which near-contact occurs at multiple levels, such as cell-wall, cell-cell, and intracellular interactions, to highlight the importance of resolving thin fluid layers in order to obtain the correct overall dynamics.<br />
<br />
===February 5 Alex Lubotzky (Hebrew University)===<br />
<br />
Title: High dimensional expanders: From Ramanujan graphs to Ramanujan complexes<br />
<br />
Abstract: <br />
<br />
Expander graphs in general, and Ramanujan graphs , in particular, have played a major role in computer science in the last 5 decades and more recently also in pure math. The first explicit construction of bounded degree expanding graphs was given by Margulis in the early 70's. In mid 80' Margulis and Lubotzky-Phillips-Sarnak provided Ramanujan graphs which are optimal such expanders. <br />
<br />
In recent years a high dimensional theory of expanders is emerging. A notion of topological expanders was defined by Gromov in 2010 who proved that the complete d-dimensional simplical complexes are such. He raised the basic question of existence of such bounded degree complexes of dimension d>1. <br />
<br />
This question was answered recently affirmatively (by T. Kaufman, D. Kazdhan and A. Lubotzky for d=2 and by S. Evra and T. Kaufman for general d) by showing that the d-skeleton of (d+1)-dimensional Ramanujan complexes provide such topological expanders. We will describe these developments and the general area of high dimensional expanders. <br />
<br />
<br />
===February 6 Alex Lubotzky (Hebrew University)===<br />
<br />
Title: Groups' approximation, stability and high dimensional expanders<br />
<br />
Abstract: <br />
<br />
Several well-known open questions, such as: are all groups sofic or hyperlinear?, have a common form: can all groups be approximated by asymptotic homomorphisms into the symmetric groups Sym(n) (in the sofic case) or the unitary groups U(n) (in the hyperlinear case)? In the case of U(n), the question can be asked with respect to different metrics and norms. We answer, for the first time, one of these versions, showing that there exist fintely presented groups which are not approximated by U(n) with respect to the Frobenius (=L_2) norm.<br />
<br />
The strategy is via the notion of "stability": some higher dimensional cohomology vanishing phenomena is proven to imply stability and using high dimensional expanders, it is shown that some non-residually finite groups (central extensions of some lattices in p-adic Lie groups) are Frobenious stable and hence cannot be Frobenius approximated. <br />
<br />
All notions will be explained. Joint work with M, De Chiffre, L. Glebsky and A. Thom.<br />
<br />
===February 9 Wes Pegden (CMU)===<br />
<br />
Title: The fractal nature of the Abelian Sandpile <br />
<br />
Abstract: The Abelian Sandpile is a simple diffusion process on the integer lattice, in which configurations of chips disperse according to a simple rule: when a vertex has at least 4 chips, it can distribute one chip to each neighbor. <br />
<br />
Introduced in the statistical physics community in the 1980s, the Abelian sandpile exhibits striking fractal behavior which long resisted rigorous mathematical analysis (or even a plausible explanation). We now have a relatively robust mathematical understanding of this fractal nature of the sandpile, which involves surprising connections between integer superharmonic functions on the lattice, discrete tilings of the plane, and Apollonian circle packings. In this talk, we will survey our work in this area, and discuss avenues of current and future research.<br />
<br />
===March 2 Aaron Bertram (Utah)===<br />
<br />
Title: Stability in Algebraic Geometry<br />
<br />
Abstract: Stability was originally introduced in algebraic geometry in the context of finding a projective quotient space for the action of an algebraic group on a projective manifold. This, in turn, led in the 1960s to a notion of slope-stability for vector bundles on a Riemann surface, which was an important tool in the classification of vector bundles. In the 1990s, mirror symmetry considerations led Michael Douglas to notions of stability for "D-branes" (on a higher-dimensional manifold) that corresponded to no previously known mathematical definition. We now understand each of these notions of stability as a distinct point of a complex "stability manifold" that is an important invariant of the (derived) category of complexes of vector bundles of a projective manifold. In this talk I want to give some examples to illustrate the various stabilities, and also to describe some current work in the area.<br />
<br />
===April 6 Edray Goins (Purdue)===<br />
<br />
Title: Toroidal Bely&#301; Pairs, Toroidal Graphs, and their Monodromy Groups<br />
<br />
Abstract: A Bely&#301; map <math> \beta: \mathbb P^1(\mathbb C) \to \mathbb P^1(\mathbb C) </math> is a rational function with at most three critical values; we may assume these values are <math> \{ 0, \, 1, \, \infty \}. </math> A Dessin d'Enfant is a planar bipartite graph obtained by considering the preimage of a path between two of these critical values, usually taken to be the line segment from 0 to 1. Such graphs can be drawn on the sphere by composing with stereographic projection: <math> \beta^{-1} \bigl( [0,1] \bigr) \subseteq \mathbb P^1(\mathbb C) \simeq S^2(\mathbb R). </math> Replacing <math> \mathbb P^1 </math> with an elliptic curve E, there is a similar definition of a Bely&#301; map <math> \beta: E(\mathbb C) \to \mathbb P^1(\mathbb C). </math> Since <math> E(\mathbb C) \simeq \mathbb T^2(\mathbb R) </math> is a torus, we call <math> (E, \beta) </math> a toroidal Bely&#301; pair. The corresponding Dessin d'Enfant can be drawn on the torus by composing with an elliptic logarithm: <math> \beta^{-1} \bigl( [0,1] \bigr) \subseteq E(\mathbb C) \simeq \mathbb T^2(\mathbb R). </math><br />
<br />
This project seeks to create a database of such Bely&#301; pairs, their corresponding Dessins d'Enfant, and their monodromy groups. For each positive integer N, there are only finitely many toroidal Bely&#301; pairs <math> (E, \beta) </math> with <math> \deg \, \beta = N. </math> Using the Hurwitz Genus formula, we can begin this database by considering all possible degree sequences <math> \mathcal D </math> on the ramification indices as multisets on three partitions of N. For each degree sequence, we compute all possible monodromy groups <math> G = \text{im} \, \bigl[ \pi_1 \bigl( \mathbb P^1(\mathbb C) - \{ 0, \, 1, \, \infty \} \bigr) \to S_N \bigr]; </math> they are the ``Galois closure'' of the group of automorphisms of the graph. Finally, for each possible monodromy group, we compute explicit formulas for Bely&#301; maps <math> \beta: E(\mathbb C) \to \mathbb P^1(\mathbb C) </math> associated to some elliptic curve <math> E: \ y^2 = x^3 + A \, x + B. </math> We will discuss some of the challenges of determining the structure of these groups, and present visualizations of group actions on the torus. <br />
<br />
This work is part of PRiME (Purdue Research in Mathematics Experience) with Chineze Christopher, Robert Dicks, Gina Ferolito, Joseph Sauder, and Danika Van Niel with assistance by Edray Goins and Abhishek Parab.<br />
<br />
== Past Colloquia ==<br />
<br />
[[Colloquia/Blank|Blank Colloquia]]<br />
<br />
[[Colloquia/Fall2017|Fall 2017]]<br />
<br />
[[Colloquia/Spring2017|Spring 2017]]<br />
<br />
[[Archived Fall 2016 Colloquia|Fall 2016]]<br />
<br />
[[Colloquia/Spring2016|Spring 2016]]<br />
<br />
[[Colloquia/Fall2015|Fall 2015]]<br />
<br />
[[Colloquia/Spring2014|Spring 2015]]<br />
<br />
[[Colloquia/Fall2014|Fall 2014]]<br />
<br />
[[Colloquia/Spring2014|Spring 2014]]<br />
<br />
[[Colloquia/Fall2013|Fall 2013]]<br />
<br />
[[Colloquia 2012-2013|Spring 2013]]<br />
<br />
[[Colloquia 2012-2013#Fall 2012|Fall 2012]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Colloquia/Fall18&diff=15207Colloquia/Fall182018-03-05T15:24:05Z<p>Rdavis: </p>
<hr />
<div>= Mathematics Colloquium =<br />
<br />
All colloquia are on Fridays at 4:00 pm in Van Vleck B239, '''unless otherwise indicated'''.<br />
<br />
== Spring 2018 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date <br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
|-<br />
|January 29 (Monday)<br />
| [http://www.math.columbia.edu/~chaoli/ Li Chao] (Columbia)<br />
|[[#January 29 Li Chao (Columbia)| Elliptic curves and Goldfeld's conjecture ]]<br />
| Jordan Ellenberg<br />
|<br />
|-<br />
|February 2 (Room: 911)<br />
| [https://scholar.harvard.edu/tfai/home Thomas Fai] (Harvard)<br />
|[[#February 2 Thomas Fai (Harvard)| The Lubricated Immersed Boundary Method ]]<br />
| Spagnolie, Smith<br />
|<br />
|-<br />
|February 5 (Monday, Room: 911)<br />
| [http://www.ma.huji.ac.il/~alexlub/ Alex Lubotzky] (Hebrew University) <br />
|[[#February 5 Alex Lubotzky (Hebrew University)| High dimensional expanders: From Ramanujan graphs to Ramanujan complexes ]]<br />
| Ellenberg, Gurevitch<br />
|<br />
|-<br />
|February 6 (Tuesday 2 pm, Room 911)<br />
| [http://www.ma.huji.ac.il/~alexlub/ Alex Lubotzky] (Hebrew University) <br />
|[[#February 6 Alex Lubotzky (Hebrew University)| Groups' approximation, stability and high dimensional expanders ]]<br />
| Ellenberg, Gurevitch<br />
|<br />
|-<br />
|February 9<br />
| [http://www.math.cmu.edu/~wes/ Wes Pegden] (CMU)<br />
|[[#February 9 Wes Pegden (CMU)| The fractal nature of the Abelian Sandpile ]]<br />
| Roch<br />
|<br />
|-<br />
|March 2<br />
| [http://www.math.utah.edu/~bertram/ Aaron Bertram] (University of Utah)<br />
|[[#March 2 Aaron Bertram (Utah)| Stability in Algebraic Geometry ]]<br />
| Caldararu<br />
|<br />
|-<br />
| March 16<br />
|[https://math.dartmouth.edu/~annegelb/ Anne Gelb] (Dartmouth)<br />
|[[# TBA| TBA ]]<br />
| WIMAW<br />
|<br />
|-<br />
|April 4 (Wednesday)<br />
| [http://math.ucr.edu/home/baez/ John Baez] (UC Riverside)<br />
|[[# TBA| TBA ]]<br />
| Craciun<br />
|<br />
|-<br />
| April 6<br />
| [https://www.math.purdue.edu/~egoins Edray Goins] (Purdue)<br />
|[[# Edray Goins| TBA ]]<br />
| Melanie<br />
|<br />
|-<br />
| April 13<br />
| [https://www.math.brown.edu/~jpipher/ Jill Pipher] (Brown)<br />
|[[# TBA| TBA ]]<br />
| WIMAW<br />
|<br />
|-<br />
| April 20<br />
| Xiuxiong Chen(Stony Brook University)<br />
|[[# Xiuxiong Chen| TBA ]]<br />
| Bing Wang<br />
|<br />
|-<br />
| April 25 (Wednesday)<br />
| [http://www.f.waseda.jp/hitoshi.ishii/ Hitoshi Ishii] (Waseda University) Wasow lecture<br />
|[[# TBA| TBA ]]<br />
| Tran<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|}<br />
<br />
== Spring Abstracts ==<br />
<br />
<br />
===January 29 Li Chao (Columbia)===<br />
<br />
Title: Elliptic curves and Goldfeld's conjecture<br />
<br />
Abstract: <br />
An elliptic curve is a plane curve defined by a cubic equation. Determining whether such an equation has infinitely many rational solutions has been a central problem in number theory for centuries, which lead to the celebrated conjecture of Birch and Swinnerton-Dyer. Within a family of elliptic curves (such as the Mordell curve family y^2=x^3-d), a conjecture of Goldfeld further predicts that there should be infinitely many rational solutions exactly half of the time. We will start with a history of this problem, discuss our recent work (with D. Kriz) towards Goldfeld's conjecture and illustrate the key ideas and ingredients behind these new progresses.<br />
<br />
=== February 2 Thomas Fai (Harvard) ===<br />
<br />
Title: The Lubricated Immersed Boundary Method<br />
<br />
Abstract:<br />
Many real-world examples of fluid-structure interaction, including the transit of red blood cells through the narrow slits in the spleen, involve the near-contact of elastic structures separated by thin layers of fluid. The separation of length scales between these fine lubrication layers and the larger elastic objects poses significant computational challenges. Motivated by the challenge of resolving such multiscale problems, we introduce an immersed boundary method that uses elements of lubrication theory to resolve thin fluid layers between immersed boundaries. We apply this method to two-dimensional flows of increasing complexity, including eccentric rotating cylinders and elastic vesicles near walls in shear flow, to show its increased accuracy compared to the classical immersed boundary method. We present preliminary simulation results of cell suspensions, a problem in which near-contact occurs at multiple levels, such as cell-wall, cell-cell, and intracellular interactions, to highlight the importance of resolving thin fluid layers in order to obtain the correct overall dynamics.<br />
<br />
===February 5 Alex Lubotzky (Hebrew University)===<br />
<br />
Title: High dimensional expanders: From Ramanujan graphs to Ramanujan complexes<br />
<br />
Abstract: <br />
<br />
Expander graphs in general, and Ramanujan graphs , in particular, have played a major role in computer science in the last 5 decades and more recently also in pure math. The first explicit construction of bounded degree expanding graphs was given by Margulis in the early 70's. In mid 80' Margulis and Lubotzky-Phillips-Sarnak provided Ramanujan graphs which are optimal such expanders. <br />
<br />
In recent years a high dimensional theory of expanders is emerging. A notion of topological expanders was defined by Gromov in 2010 who proved that the complete d-dimensional simplical complexes are such. He raised the basic question of existence of such bounded degree complexes of dimension d>1. <br />
<br />
This question was answered recently affirmatively (by T. Kaufman, D. Kazdhan and A. Lubotzky for d=2 and by S. Evra and T. Kaufman for general d) by showing that the d-skeleton of (d+1)-dimensional Ramanujan complexes provide such topological expanders. We will describe these developments and the general area of high dimensional expanders. <br />
<br />
<br />
===February 6 Alex Lubotzky (Hebrew University)===<br />
<br />
Title: Groups' approximation, stability and high dimensional expanders<br />
<br />
Abstract: <br />
<br />
Several well-known open questions, such as: are all groups sofic or hyperlinear?, have a common form: can all groups be approximated by asymptotic homomorphisms into the symmetric groups Sym(n) (in the sofic case) or the unitary groups U(n) (in the hyperlinear case)? In the case of U(n), the question can be asked with respect to different metrics and norms. We answer, for the first time, one of these versions, showing that there exist fintely presented groups which are not approximated by U(n) with respect to the Frobenius (=L_2) norm.<br />
<br />
The strategy is via the notion of "stability": some higher dimensional cohomology vanishing phenomena is proven to imply stability and using high dimensional expanders, it is shown that some non-residually finite groups (central extensions of some lattices in p-adic Lie groups) are Frobenious stable and hence cannot be Frobenius approximated. <br />
<br />
All notions will be explained. Joint work with M, De Chiffre, L. Glebsky and A. Thom.<br />
<br />
===February 9 Wes Pegden (CMU)===<br />
<br />
Title: The fractal nature of the Abelian Sandpile <br />
<br />
Abstract: The Abelian Sandpile is a simple diffusion process on the integer lattice, in which configurations of chips disperse according to a simple rule: when a vertex has at least 4 chips, it can distribute one chip to each neighbor. <br />
<br />
Introduced in the statistical physics community in the 1980s, the Abelian sandpile exhibits striking fractal behavior which long resisted rigorous mathematical analysis (or even a plausible explanation). We now have a relatively robust mathematical understanding of this fractal nature of the sandpile, which involves surprising connections between integer superharmonic functions on the lattice, discrete tilings of the plane, and Apollonian circle packings. In this talk, we will survey our work in this area, and discuss avenues of current and future research.<br />
<br />
===March 2 Aaron Bertram (Utah)===<br />
<br />
Title: Stability in Algebraic Geometry<br />
<br />
Abstract: Stability was originally introduced in algebraic geometry in the context of finding a projective quotient space for the action of an algebraic group on a projective manifold. This, in turn, led in the 1960s to a notion of slope-stability for vector bundles on a Riemann surface, which was an important tool in the classification of vector bundles. In the 1990s, mirror symmetry considerations led Michael Douglas to notions of stability for "D-branes" (on a higher-dimensional manifold) that corresponded to no previously known mathematical definition. We now understand each of these notions of stability as a distinct point of a complex "stability manifold" that is an important invariant of the (derived) category of complexes of vector bundles of a projective manifold. In this talk I want to give some examples to illustrate the various stabilities, and also to describe some current work in the area.<br />
<br />
===April 6 Edray Goins (Purdue)===<br />
<br />
Title: Toroidal Belyi Pairs, Toroidal Graphs, and their Monodromy Groups<br />
<br />
Abstract: A Belyi map <math> \beta: \mathbb P^1(\mathbb C) \to \mathbb P^1(\mathbb C) </math> is a rational function with at most three critical values; we may assume these values are <math> \{ 0, \, 1, \, \infty \}. </math> A Dessin d'Enfant is a planar bipartite graph obtained by considering the preimage of a path between two of these critical values, usually taken to be the line segment from 0 to 1. Such graphs can be drawn on the sphere by composing with stereographic projection: <math> \beta^{-1} \bigl( [0,1] \bigr) \subseteq \mathbb P^1(\mathbb C) \simeq S^2(\mathbb R). </math> Replacing <math> \mathbb P^1 </math> with an elliptic curve E, there is a similar definition of a Belyi map <math> \beta: E(\mathbb C) \to \mathbb P^1(\mathbb C). </math> Since <math> E(\mathbb C) \simeq \mathbb T^2(\mathbb R) </math> is a torus, we call <math> (E, \beta) </math> a toroidal Belyi pair. The corresponding Dessin d'Enfant can be drawn on the torus by composing with an elliptic logarithm: <math> \beta^{-1} \bigl( [0,1] \bigr) \subseteq E(\mathbb C) \simeq \mathbb T^2(\mathbb R). </math><br />
<br />
This project seeks to create a database of such Belyi pairs, their corresponding Dessins d'Enfant, and their monodromy groups. For each positive integer N, there are only finitely many toroidal Belyi pairs <math> (E, \beta) </math> with <math> \deg \, \beta = N. </math> Using the Hurwitz Genus formula, we can begin this database by considering all possible degree sequences <math> \mathcal D </math> on the ramification indices as multisets on three partitions of N. For each degree sequence, we compute all possible monodromy groups <math> G = \text{im} \, \bigl[ \pi_1 \bigl( \mathbb P^1(\mathbb C) - \{ 0, \, 1, \, \infty \} \bigr) \to S_N \bigr]; </math> they are the ``Galois closure'' of the group of automorphisms of the graph. Finally, for each possible monodromy group, we compute explicit formulas for Belyi maps <math> \beta: E(\mathbb C) \to \mathbb P^1(\mathbb C) </math> associated to some elliptic curve <math> E: \ y^2 = x^3 + A \, x + B. </math> We will discuss some of the challenges of determining the structure of these groups, and present visualizations of group actions on the torus. <br />
<br />
This work is part of PRiME (Purdue Research in Mathematics Experience) with Chineze Christopher, Robert Dicks, Gina Ferolito, Joseph Sauder, and Danika Van Niel with assistance by Edray Goins and Abhishek Parab.<br />
<br />
== Past Colloquia ==<br />
<br />
[[Colloquia/Blank|Blank Colloquia]]<br />
<br />
[[Colloquia/Fall2017|Fall 2017]]<br />
<br />
[[Colloquia/Spring2017|Spring 2017]]<br />
<br />
[[Archived Fall 2016 Colloquia|Fall 2016]]<br />
<br />
[[Colloquia/Spring2016|Spring 2016]]<br />
<br />
[[Colloquia/Fall2015|Fall 2015]]<br />
<br />
[[Colloquia/Spring2014|Spring 2015]]<br />
<br />
[[Colloquia/Fall2014|Fall 2014]]<br />
<br />
[[Colloquia/Spring2014|Spring 2014]]<br />
<br />
[[Colloquia/Fall2013|Fall 2013]]<br />
<br />
[[Colloquia 2012-2013|Spring 2013]]<br />
<br />
[[Colloquia 2012-2013#Fall 2012|Fall 2012]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Colloquia/Fall18&diff=15206Colloquia/Fall182018-03-05T14:20:06Z<p>Rdavis: </p>
<hr />
<div>= Mathematics Colloquium =<br />
<br />
All colloquia are on Fridays at 4:00 pm in Van Vleck B239, '''unless otherwise indicated'''.<br />
<br />
== Spring 2018 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date <br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
|-<br />
|January 29 (Monday)<br />
| [http://www.math.columbia.edu/~chaoli/ Li Chao] (Columbia)<br />
|[[#January 29 Li Chao (Columbia)| Elliptic curves and Goldfeld's conjecture ]]<br />
| Jordan Ellenberg<br />
|<br />
|-<br />
|February 2 (Room: 911)<br />
| [https://scholar.harvard.edu/tfai/home Thomas Fai] (Harvard)<br />
|[[#February 2 Thomas Fai (Harvard)| The Lubricated Immersed Boundary Method ]]<br />
| Spagnolie, Smith<br />
|<br />
|-<br />
|February 5 (Monday, Room: 911)<br />
| [http://www.ma.huji.ac.il/~alexlub/ Alex Lubotzky] (Hebrew University) <br />
|[[#February 5 Alex Lubotzky (Hebrew University)| High dimensional expanders: From Ramanujan graphs to Ramanujan complexes ]]<br />
| Ellenberg, Gurevitch<br />
|<br />
|-<br />
|February 6 (Tuesday 2 pm, Room 911)<br />
| [http://www.ma.huji.ac.il/~alexlub/ Alex Lubotzky] (Hebrew University) <br />
|[[#February 6 Alex Lubotzky (Hebrew University)| Groups' approximation, stability and high dimensional expanders ]]<br />
| Ellenberg, Gurevitch<br />
|<br />
|-<br />
|February 9<br />
| [http://www.math.cmu.edu/~wes/ Wes Pegden] (CMU)<br />
|[[#February 9 Wes Pegden (CMU)| The fractal nature of the Abelian Sandpile ]]<br />
| Roch<br />
|<br />
|-<br />
|March 2<br />
| [http://www.math.utah.edu/~bertram/ Aaron Bertram] (University of Utah)<br />
|[[#March 2 Aaron Bertram (Utah)| Stability in Algebraic Geometry ]]<br />
| Caldararu<br />
|<br />
|-<br />
| March 16<br />
|[https://math.dartmouth.edu/~annegelb/ Anne Gelb] (Dartmouth)<br />
|[[# TBA| TBA ]]<br />
| WIMAW<br />
|<br />
|-<br />
|April 4 (Wednesday)<br />
| [http://math.ucr.edu/home/baez/ John Baez] (UC Riverside)<br />
|[[# TBA| TBA ]]<br />
| Craciun<br />
|<br />
|-<br />
| April 6<br />
| [https://www.math.purdue.edu/~egoins Edray Goins] (Purdue)<br />
|[[# Edray Goins| TBA ]]<br />
| Melanie<br />
|<br />
|-<br />
| April 13<br />
| [https://www.math.brown.edu/~jpipher/ Jill Pipher] (Brown)<br />
|[[# TBA| TBA ]]<br />
| WIMAW<br />
|<br />
|-<br />
| April 20<br />
| Xiuxiong Chen(Stony Brook University)<br />
|[[# Xiuxiong Chen| TBA ]]<br />
| Bing Wang<br />
|<br />
|-<br />
| April 25 (Wednesday)<br />
| [http://www.f.waseda.jp/hitoshi.ishii/ Hitoshi Ishii] (Waseda University) Wasow lecture<br />
|[[# TBA| TBA ]]<br />
| Tran<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|}<br />
<br />
== Spring Abstracts ==<br />
<br />
<br />
===January 29 Li Chao (Columbia)===<br />
<br />
Title: Elliptic curves and Goldfeld's conjecture<br />
<br />
Abstract: <br />
An elliptic curve is a plane curve defined by a cubic equation. Determining whether such an equation has infinitely many rational solutions has been a central problem in number theory for centuries, which lead to the celebrated conjecture of Birch and Swinnerton-Dyer. Within a family of elliptic curves (such as the Mordell curve family y^2=x^3-d), a conjecture of Goldfeld further predicts that there should be infinitely many rational solutions exactly half of the time. We will start with a history of this problem, discuss our recent work (with D. Kriz) towards Goldfeld's conjecture and illustrate the key ideas and ingredients behind these new progresses.<br />
<br />
=== February 2 Thomas Fai (Harvard) ===<br />
<br />
Title: The Lubricated Immersed Boundary Method<br />
<br />
Abstract:<br />
Many real-world examples of fluid-structure interaction, including the transit of red blood cells through the narrow slits in the spleen, involve the near-contact of elastic structures separated by thin layers of fluid. The separation of length scales between these fine lubrication layers and the larger elastic objects poses significant computational challenges. Motivated by the challenge of resolving such multiscale problems, we introduce an immersed boundary method that uses elements of lubrication theory to resolve thin fluid layers between immersed boundaries. We apply this method to two-dimensional flows of increasing complexity, including eccentric rotating cylinders and elastic vesicles near walls in shear flow, to show its increased accuracy compared to the classical immersed boundary method. We present preliminary simulation results of cell suspensions, a problem in which near-contact occurs at multiple levels, such as cell-wall, cell-cell, and intracellular interactions, to highlight the importance of resolving thin fluid layers in order to obtain the correct overall dynamics.<br />
<br />
===February 5 Alex Lubotzky (Hebrew University)===<br />
<br />
Title: High dimensional expanders: From Ramanujan graphs to Ramanujan complexes<br />
<br />
Abstract: <br />
<br />
Expander graphs in general, and Ramanujan graphs , in particular, have played a major role in computer science in the last 5 decades and more recently also in pure math. The first explicit construction of bounded degree expanding graphs was given by Margulis in the early 70's. In mid 80' Margulis and Lubotzky-Phillips-Sarnak provided Ramanujan graphs which are optimal such expanders. <br />
<br />
In recent years a high dimensional theory of expanders is emerging. A notion of topological expanders was defined by Gromov in 2010 who proved that the complete d-dimensional simplical complexes are such. He raised the basic question of existence of such bounded degree complexes of dimension d>1. <br />
<br />
This question was answered recently affirmatively (by T. Kaufman, D. Kazdhan and A. Lubotzky for d=2 and by S. Evra and T. Kaufman for general d) by showing that the d-skeleton of (d+1)-dimensional Ramanujan complexes provide such topological expanders. We will describe these developments and the general area of high dimensional expanders. <br />
<br />
<br />
===February 6 Alex Lubotzky (Hebrew University)===<br />
<br />
Title: Groups' approximation, stability and high dimensional expanders<br />
<br />
Abstract: <br />
<br />
Several well-known open questions, such as: are all groups sofic or hyperlinear?, have a common form: can all groups be approximated by asymptotic homomorphisms into the symmetric groups Sym(n) (in the sofic case) or the unitary groups U(n) (in the hyperlinear case)? In the case of U(n), the question can be asked with respect to different metrics and norms. We answer, for the first time, one of these versions, showing that there exist fintely presented groups which are not approximated by U(n) with respect to the Frobenius (=L_2) norm.<br />
<br />
The strategy is via the notion of "stability": some higher dimensional cohomology vanishing phenomena is proven to imply stability and using high dimensional expanders, it is shown that some non-residually finite groups (central extensions of some lattices in p-adic Lie groups) are Frobenious stable and hence cannot be Frobenius approximated. <br />
<br />
All notions will be explained. Joint work with M, De Chiffre, L. Glebsky and A. Thom.<br />
<br />
===February 9 Wes Pegden (CMU)===<br />
<br />
Title: The fractal nature of the Abelian Sandpile <br />
<br />
Abstract: The Abelian Sandpile is a simple diffusion process on the integer lattice, in which configurations of chips disperse according to a simple rule: when a vertex has at least 4 chips, it can distribute one chip to each neighbor. <br />
<br />
Introduced in the statistical physics community in the 1980s, the Abelian sandpile exhibits striking fractal behavior which long resisted rigorous mathematical analysis (or even a plausible explanation). We now have a relatively robust mathematical understanding of this fractal nature of the sandpile, which involves surprising connections between integer superharmonic functions on the lattice, discrete tilings of the plane, and Apollonian circle packings. In this talk, we will survey our work in this area, and discuss avenues of current and future research.<br />
<br />
===March 2 Aaron Bertram (Utah)===<br />
<br />
Title: Stability in Algebraic Geometry<br />
<br />
Abstract: Stability was originally introduced in algebraic geometry in the context of finding a projective quotient space for the action of an algebraic group on a projective manifold. This, in turn, led in the 1960s to a notion of slope-stability for vector bundles on a Riemann surface, which was an important tool in the classification of vector bundles. In the 1990s, mirror symmetry considerations led Michael Douglas to notions of stability for "D-branes" (on a higher-dimensional manifold) that corresponded to no previously known mathematical definition. We now understand each of these notions of stability as a distinct point of a complex "stability manifold" that is an important invariant of the (derived) category of complexes of vector bundles of a projective manifold. In this talk I want to give some examples to illustrate the various stabilities, and also to describe some current work in the area.<br />
<br />
== Past Colloquia ==<br />
<br />
[[Colloquia/Blank|Blank Colloquia]]<br />
<br />
[[Colloquia/Fall2017|Fall 2017]]<br />
<br />
[[Colloquia/Spring2017|Spring 2017]]<br />
<br />
[[Archived Fall 2016 Colloquia|Fall 2016]]<br />
<br />
[[Colloquia/Spring2016|Spring 2016]]<br />
<br />
[[Colloquia/Fall2015|Fall 2015]]<br />
<br />
[[Colloquia/Spring2014|Spring 2015]]<br />
<br />
[[Colloquia/Fall2014|Fall 2014]]<br />
<br />
[[Colloquia/Spring2014|Spring 2014]]<br />
<br />
[[Colloquia/Fall2013|Fall 2013]]<br />
<br />
[[Colloquia 2012-2013|Spring 2013]]<br />
<br />
[[Colloquia 2012-2013#Fall 2012|Fall 2012]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Colloquia/Fall18&diff=15205Colloquia/Fall182018-03-05T14:16:00Z<p>Rdavis: </p>
<hr />
<div>= Mathematics Colloquium =<br />
<br />
All colloquia are on Fridays at 4:00 pm in Van Vleck B239, '''unless otherwise indicated'''.<br />
<br />
== Spring 2018 ==<br />
<br />
{| cellpadding="8"<br />
!align="left" | date <br />
!align="left" | speaker<br />
!align="left" | title<br />
!align="left" | host(s)<br />
|-<br />
|January 29 (Monday)<br />
| [http://www.math.columbia.edu/~chaoli/ Li Chao] (Columbia)<br />
|[[#January 29 Li Chao (Columbia)| Elliptic curves and Goldfeld's conjecture ]]<br />
| Jordan Ellenberg<br />
|<br />
|-<br />
|February 2 (Room: 911)<br />
| [https://scholar.harvard.edu/tfai/home Thomas Fai] (Harvard)<br />
|[[#February 2 Thomas Fai (Harvard)| The Lubricated Immersed Boundary Method ]]<br />
| Spagnolie, Smith<br />
|<br />
|-<br />
|February 5 (Monday, Room: 911)<br />
| [http://www.ma.huji.ac.il/~alexlub/ Alex Lubotzky] (Hebrew University) <br />
|[[#February 5 Alex Lubotzky (Hebrew University)| High dimensional expanders: From Ramanujan graphs to Ramanujan complexes ]]<br />
| Ellenberg, Gurevitch<br />
|<br />
|-<br />
|February 6 (Tuesday 2 pm, Room 911)<br />
| [http://www.ma.huji.ac.il/~alexlub/ Alex Lubotzky] (Hebrew University) <br />
|[[#February 6 Alex Lubotzky (Hebrew University)| Groups' approximation, stability and high dimensional expanders ]]<br />
| Ellenberg, Gurevitch<br />
|<br />
|-<br />
|February 9<br />
| [http://www.math.cmu.edu/~wes/ Wes Pegden] (CMU)<br />
|[[#February 9 Wes Pegden (CMU)| The fractal nature of the Abelian Sandpile ]]<br />
| Roch<br />
|<br />
|-<br />
|March 2<br />
| [http://www.math.utah.edu/~bertram/ Aaron Bertram] (University of Utah)<br />
|[[#March 2 Aaron Bertram (Utah)| Stability in Algebraic Geometry ]]<br />
| Caldararu<br />
|<br />
|-<br />
| March 16<br />
|[https://math.dartmouth.edu/~annegelb/ Anne Gelb] (Dartmouth)<br />
|[[# TBA| TBA ]]<br />
| WIMAW<br />
|<br />
|-<br />
|April 4 (Wednesday)<br />
| [http://math.ucr.edu/home/baez/ John Baez] (UC Riverside)<br />
|[[# TBA| TBA ]]<br />
| Craciun<br />
|<br />
|-<br />
| April 6<br />
| [https://www.math.purdue.edu/people/bio/egoins/home/ Edray Goins] (Purdue)<br />
|[[# Edray Goins| TBA ]]<br />
| Melanie<br />
|<br />
|-<br />
| April 13<br />
| [https://www.math.brown.edu/~jpipher/ Jill Pipher] (Brown)<br />
|[[# TBA| TBA ]]<br />
| WIMAW<br />
|<br />
|-<br />
| April 20<br />
| Xiuxiong Chen(Stony Brook University)<br />
|[[# Xiuxiong Chen| TBA ]]<br />
| Bing Wang<br />
|<br />
|-<br />
| April 25 (Wednesday)<br />
| [http://www.f.waseda.jp/hitoshi.ishii/ Hitoshi Ishii] (Waseda University) Wasow lecture<br />
|[[# TBA| TBA ]]<br />
| Tran<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|-<br />
|date<br />
| person (institution)<br />
|[[# TBA| TBA ]]<br />
| hosting faculty<br />
|<br />
|}<br />
<br />
== Spring Abstracts ==<br />
<br />
<br />
===January 29 Li Chao (Columbia)===<br />
<br />
Title: Elliptic curves and Goldfeld's conjecture<br />
<br />
Abstract: <br />
An elliptic curve is a plane curve defined by a cubic equation. Determining whether such an equation has infinitely many rational solutions has been a central problem in number theory for centuries, which lead to the celebrated conjecture of Birch and Swinnerton-Dyer. Within a family of elliptic curves (such as the Mordell curve family y^2=x^3-d), a conjecture of Goldfeld further predicts that there should be infinitely many rational solutions exactly half of the time. We will start with a history of this problem, discuss our recent work (with D. Kriz) towards Goldfeld's conjecture and illustrate the key ideas and ingredients behind these new progresses.<br />
<br />
=== February 2 Thomas Fai (Harvard) ===<br />
<br />
Title: The Lubricated Immersed Boundary Method<br />
<br />
Abstract:<br />
Many real-world examples of fluid-structure interaction, including the transit of red blood cells through the narrow slits in the spleen, involve the near-contact of elastic structures separated by thin layers of fluid. The separation of length scales between these fine lubrication layers and the larger elastic objects poses significant computational challenges. Motivated by the challenge of resolving such multiscale problems, we introduce an immersed boundary method that uses elements of lubrication theory to resolve thin fluid layers between immersed boundaries. We apply this method to two-dimensional flows of increasing complexity, including eccentric rotating cylinders and elastic vesicles near walls in shear flow, to show its increased accuracy compared to the classical immersed boundary method. We present preliminary simulation results of cell suspensions, a problem in which near-contact occurs at multiple levels, such as cell-wall, cell-cell, and intracellular interactions, to highlight the importance of resolving thin fluid layers in order to obtain the correct overall dynamics.<br />
<br />
===February 5 Alex Lubotzky (Hebrew University)===<br />
<br />
Title: High dimensional expanders: From Ramanujan graphs to Ramanujan complexes<br />
<br />
Abstract: <br />
<br />
Expander graphs in general, and Ramanujan graphs , in particular, have played a major role in computer science in the last 5 decades and more recently also in pure math. The first explicit construction of bounded degree expanding graphs was given by Margulis in the early 70's. In mid 80' Margulis and Lubotzky-Phillips-Sarnak provided Ramanujan graphs which are optimal such expanders. <br />
<br />
In recent years a high dimensional theory of expanders is emerging. A notion of topological expanders was defined by Gromov in 2010 who proved that the complete d-dimensional simplical complexes are such. He raised the basic question of existence of such bounded degree complexes of dimension d>1. <br />
<br />
This question was answered recently affirmatively (by T. Kaufman, D. Kazdhan and A. Lubotzky for d=2 and by S. Evra and T. Kaufman for general d) by showing that the d-skeleton of (d+1)-dimensional Ramanujan complexes provide such topological expanders. We will describe these developments and the general area of high dimensional expanders. <br />
<br />
<br />
===February 6 Alex Lubotzky (Hebrew University)===<br />
<br />
Title: Groups' approximation, stability and high dimensional expanders<br />
<br />
Abstract: <br />
<br />
Several well-known open questions, such as: are all groups sofic or hyperlinear?, have a common form: can all groups be approximated by asymptotic homomorphisms into the symmetric groups Sym(n) (in the sofic case) or the unitary groups U(n) (in the hyperlinear case)? In the case of U(n), the question can be asked with respect to different metrics and norms. We answer, for the first time, one of these versions, showing that there exist fintely presented groups which are not approximated by U(n) with respect to the Frobenius (=L_2) norm.<br />
<br />
The strategy is via the notion of "stability": some higher dimensional cohomology vanishing phenomena is proven to imply stability and using high dimensional expanders, it is shown that some non-residually finite groups (central extensions of some lattices in p-adic Lie groups) are Frobenious stable and hence cannot be Frobenius approximated. <br />
<br />
All notions will be explained. Joint work with M, De Chiffre, L. Glebsky and A. Thom.<br />
<br />
===February 9 Wes Pegden (CMU)===<br />
<br />
Title: The fractal nature of the Abelian Sandpile <br />
<br />
Abstract: The Abelian Sandpile is a simple diffusion process on the integer lattice, in which configurations of chips disperse according to a simple rule: when a vertex has at least 4 chips, it can distribute one chip to each neighbor. <br />
<br />
Introduced in the statistical physics community in the 1980s, the Abelian sandpile exhibits striking fractal behavior which long resisted rigorous mathematical analysis (or even a plausible explanation). We now have a relatively robust mathematical understanding of this fractal nature of the sandpile, which involves surprising connections between integer superharmonic functions on the lattice, discrete tilings of the plane, and Apollonian circle packings. In this talk, we will survey our work in this area, and discuss avenues of current and future research.<br />
<br />
===March 2 Aaron Bertram (Utah)===<br />
<br />
Title: Stability in Algebraic Geometry<br />
<br />
Abstract: Stability was originally introduced in algebraic geometry in the context of finding a projective quotient space for the action of an algebraic group on a projective manifold. This, in turn, led in the 1960s to a notion of slope-stability for vector bundles on a Riemann surface, which was an important tool in the classification of vector bundles. In the 1990s, mirror symmetry considerations led Michael Douglas to notions of stability for "D-branes" (on a higher-dimensional manifold) that corresponded to no previously known mathematical definition. We now understand each of these notions of stability as a distinct point of a complex "stability manifold" that is an important invariant of the (derived) category of complexes of vector bundles of a projective manifold. In this talk I want to give some examples to illustrate the various stabilities, and also to describe some current work in the area.<br />
<br />
== Past Colloquia ==<br />
<br />
[[Colloquia/Blank|Blank Colloquia]]<br />
<br />
[[Colloquia/Fall2017|Fall 2017]]<br />
<br />
[[Colloquia/Spring2017|Spring 2017]]<br />
<br />
[[Archived Fall 2016 Colloquia|Fall 2016]]<br />
<br />
[[Colloquia/Spring2016|Spring 2016]]<br />
<br />
[[Colloquia/Fall2015|Fall 2015]]<br />
<br />
[[Colloquia/Spring2014|Spring 2015]]<br />
<br />
[[Colloquia/Fall2014|Fall 2014]]<br />
<br />
[[Colloquia/Spring2014|Spring 2014]]<br />
<br />
[[Colloquia/Fall2013|Fall 2013]]<br />
<br />
[[Colloquia 2012-2013|Spring 2013]]<br />
<br />
[[Colloquia 2012-2013#Fall 2012|Fall 2012]]</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=NTS_ABSTRACTSpring2018&diff=15103NTS ABSTRACTSpring20182018-02-13T16:37:56Z<p>Rdavis: /* March 22 */</p>
<hr />
<div>Return to [https://www.math.wisc.edu/wiki/index.php/NTS_Spring_2018 NTS Spring 2018 ]<br />
<br />
<br />
== Jan 25 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Asif Ali Zaman '''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | A log-free zero density estimate for Rankin-Selberg $L$-functions and applications<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract:We discuss a log-free zero density estimate for Rankin-Selberg $L$-functions of the form $L(s,\pi\times\pi_0)$, where $\pi$ varies in a given set of cusp forms and $\pi_0$ is a fixed cusp form. This estimate is unconditional in many cases of interest, and holds in full generality assuming an average form of the generalized Ramanujan conjecture. There are several applications of this density estimate related to the rarity of Landau-Siegel zeros of Rankin-Selberg $L$-functions, the Chebotarev density theorem, and nontrivial bounds for torsion in class groups of number fields assuming the existence of a Siegel zero. We will highlight the latter two topics. This represents joint work with Jesse Thorner. <br />
|} <br />
</center><br />
<br />
<br><br />
<br />
== Feb 1 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Yunqing Tang'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Exceptional splitting of reductions of abelian surfaces with real multiplication<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Zywina showed that after passing to a suitable field extension, every abelian surface $A$ with real multiplication over some number field has geometrically simple reduction modulo $\frak{p}$ for a density one set of primes $\frak{p}$. One may ask whether its complement, the density zero set of primes $\frak{p}$ such that the reduction of $A$ modulo $\frak{p}$ is not geometrically simple, is infinite. Such question is analogous to the study of exceptional mod $\frak{p}$ isogeny between two elliptic curves in the recent work of Charles. In this talk, I will show that abelian surfaces over number fields with real multiplication have infinitely many non-geometrically-simple reductions. This is joint work with Ananth Shankar.<br />
<br />
|} <br />
</center><br />
<br />
<br />
<br />
== Feb 8 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Roman Fedorov'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | A conjecture of Grothendieck and Serre on principal bundles in mixed characteristic<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: Let G be a reductive group scheme over a regular local ring R. An old conjecture of Grothendieck and Serre predicts that such a principal bundle is trivial, if it is trivial over the fraction field of R. The conjecture has recently been proved in the "geometric" case, that is, when R contains a field. In the remaining case, the difficulty comes from the fact, that the situation is more rigid, so that a certain general position argument does not go through. I will discuss this difficulty and a way to circumvent it to obtain some partial results.<br />
<br />
|} <br />
</center><br />
<br />
== Feb 13==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Frank Calegari'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Recent Progress in Modularity<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: We survey some recent work in modularity lifting, and also describe some applications of these results. This will be based partly on joint work with Allen, Caraiani, Gee, Helm, Le Hung, Newton, Scholze, Taylor, and Thorne, and also on joint work with Boxer, Gee, and Pilloni.<br />
<br />
|} <br />
</center><br />
<br />
== Feb 15 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Junho Peter Whang'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Integral points and curves on moduli of local systems<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: We consider the Diophantine geometry of moduli spaces for <br />
special linear rank two local systems on surfaces with fixed boundary <br />
traces. After motivating their Diophantine study, we establish a <br />
structure theorem for their integral points via mapping class group <br />
descent, generalizing classical work of Markoff (1880). We also obtain <br />
Diophantine results for algebraic curves in these moduli spaces, <br />
including effective finiteness of imaginary quadratic integral points <br />
for non-special curves.<br />
<br />
|} <br />
</center><br />
<br />
== Feb 22 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Yifan Yang'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Rational torsion on the generalized Jacobian of a modular curve with cuspidal modulus<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: In this talk we consider the rational torsion<br />
subgroup of the generalized Jacobian of the modular<br />
curve X_0(N) with respect to a reduced divisor given<br />
by the sum of all cusps. When N=p is a prime, we find<br />
that the rational torsion subgroup is always cyclic<br />
of order 2 (while that of the usual Jacobian of X_0(p)<br />
grows linearly as p tends to infinity, according to a<br />
well-known result of Mazur). Subject to some unproven<br />
conjecture about the rational torsions of the Jacobian<br />
of X_0(p^n), we also determine the structure of the<br />
rational torsion subgroup of the generalized Jacobian<br />
of X_0(p^n). This is a joint work with Takao Yamazaki.<br />
<br />
|} <br />
</center><br />
<br><br />
<br />
== March 22 ==<br />
<br />
<center><br />
{| style="color:black; font-size:100%" table border="2" cellpadding="10" width="700" cellspacing="20"<br />
|-<br />
| bgcolor="#F0A0A0" align="center" style="font-size:125%" | '''Fang-Ting Tu'''<br />
|-<br />
| bgcolor="#BCD2EE" align="center" | Title: Supercongrence for Rigid Hypergeometric Calabi-Yau Threefolds<br />
|-<br />
| bgcolor="#BCD2EE" | Abstract: <br />
This is a joint work with Ling Long, Noriko Yui, and Wadim Zudilin. We establish the supercongruences for the rigid hypergeometric Calabi-Yau threefolds over rational numbers. These supercongruences were conjectured by Rodriguez-Villeagas in 2003. In this work, we use two different approaches. The first method is based on Dwork's p-adic unit root theory, and the other is based on the theory of hypergeometric motives and hypergeometric functions over finite fields. In this talk, I will introduce the first method, which allows us to obtain the supercongruences for ordinary primes. <br />
<br />
<br />
|} <br />
</center><br />
<br></div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Abelian_Varieties_2018&diff=15050Abelian Varieties 20182018-02-07T23:07:49Z<p>Rdavis: </p>
<hr />
<div>== Overview ==<br />
This reading seminar will cover Kempf's "Complex Abelian Varieties and Theta Functions" book. Talks will be Mondays, 4:00-4:50 in Room B139.<br />
<br />
We can try to cover Chapters 1-7 and Chapter 11 and maybe some topics from the other chapters of Birkenhake and Lange's "Complex Abelian Varieties" as time permits.<br />
<br />
== Talk Schedule ==<br />
The following schedule might be adjusted as we go, depending on whether it seems too fast or not.<br />
<br />
Here is the [[https://www.math.wisc.edu/wiki/images/TOC.pdf Table of Contents]] of Kempf's book.<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | sections<br />
<br />
|-<br />
|February 7<br />
|Rachel Davis<br />
|1.1-1.3<br />
|-<br />
|February 12<br />
|Soumya Sankar<br />
|1.4-1.5<br />
|-<br />
|February 19<br />
|Michael Brown<br />
|2.1-2.2<br />
|-<br />
|February 26<br />
|Solly Parenti<br />
|2.3-2.4<br />
|-<br />
|March 5<br />
|TBD<br />
|3.1-3.3<br />
|-<br />
|March 12<br />
|Moisés Herradón Cueto<br />
|3.4-3.6<br />
|-<br />
|March 19<br />
|TBD<br />
|4<br />
|-<br />
|March 26<br />
|No meeting<br />
|Spring Break<br />
|-<br />
|April 2<br />
|Mao Li<br />
|5.1-5.3<br />
|-<br />
|April 9<br />
|TBD<br />
|5.3-5.5<br />
|-<br />
|April 16<br />
|TBD<br />
|6<br />
|-<br />
|April 23<br />
|TBD<br />
|7<br />
|-<br />
|April 30<br />
|TBD<br />
|11<br />
|-<br />
|May 7<br />
|TBD<br />
|???<br />
|-<br />
|}</div>Rdavishttp://www.math.wisc.edu/wiki/index.php?title=Abelian_Varieties_2018&diff=14855Abelian Varieties 20182018-01-24T18:49:52Z<p>Rdavis: </p>
<hr />
<div>== Overview ==<br />
This reading seminar will cover Kempf's "Complex Abelian Varieties and Theta Functions" book. Talks will be Mondays, 4:00-4:50 in Room B139.<br />
<br />
We can try to cover Chapters 1-7 and Chapter 11 and maybe some topics from the other chapters of Birkenhake and Lange's "Complex Abelian Varieties" as time permits.<br />
<br />
== Talk Schedule ==<br />
The following schedule might be adjusted as we go, depending on whether it seems too fast or not.<br />
<br />
Here is the [[https://www.math.wisc.edu/wiki/images/TOC.pdf Table of Contents]] of Kempf's book.<br />
<br />
{| cellpadding="8"<br />
!align="left" | date<br />
!align="left" | speaker<br />
!align="left" | sections<br />
<br />
|-<br />
|January 29<br />
|Rachel Davis<br />
|1.1-1.3<br />
|-<br />
|February 5<br />
|TBD<br />
|1.4-1.5<br />
|-<br />
|February 12<br />
|TBD<br />
|2.1-2.2<br />
|-<br />
|February 19<br />
|TBD<br />
|2.3-2.4<br />
|-<br />
|February 26<br />
|TBD<br />
|3.1-3.3<br />
|-<br />
|March 5<br />
|TBD<br />
|3.4-3.6<br />
|-<br />
|March 12<br />
|TBD<br />
|4<br />
|-<br />
|March 19<br />
|TBD<br />
|5.1-5.3<br />
|-<br />
|March 26<br />
|No meeting<br />
|Spring Break<br />
|-<br />
|April 2<br />
|TBD<br />
|5.3-5.5<br />
|-<br />
|April 9<br />
|TBD<br />
|6<br />
|-<br />
|April 16<br />
|TBD<br />
|7<br />
|-<br />
|April 23<br />
|TBD<br />
|11<br />
|-<br />
|April 30<br />
|TBD<br />
|???<br />
|-<br />
|May 7<br />
|TBD<br />
|???<br />
|-<br />
|}</div>Rdavis