Past Probability Seminars Spring 2020: Difference between revisions

From UW-Math Wiki
Jump to navigation Jump to search
(18 intermediate revisions by 4 users not shown)
Line 1: Line 1:
__NOTOC__
__NOTOC__


= Fall 2019 =
= Spring 2020 =


<b>Thursdays in 901 Van Vleck Hall at 2:30 PM</b>, unless otherwise noted.  
<b>Thursdays in 901 Van Vleck Hall at 2:30 PM</b>, unless otherwise noted.  
Line 10: Line 10:


   
   
== September 12, 2019, [https://perso.univ-rennes1.fr/victor.kleptsyn/ Victor Kleptsyn], CNRS and University of Rennes 1 ==
== January 23, 2020, Timo Seppalainen (UW Madison) ==
'''Furstenberg theorem: now with a parameter!'''
'''Non-existence of bi-infinite geodesics in the exponential corner growth model
'''


The classical Furstenberg theorem describes the (almost sure) behaviour of a random product of independent matrices; their norms turn out to grow exponentially. In our joint work with A. Gorodetski, we study what happens if the random matrices depend on an additional parameter.
Whether bi-infinite geodesics exist has been a significant open problem in first- and last-passage percolation since the mid-80s.  A non-existence proof  in the case of directed planar last-passage percolation with exponential weights was posted by Basu, Hoffman and Sly in  November 2018. Their proof utilizes estimates from integrable probability.   This talk describes an independent proof completed 10 months later that relies on couplings, coarse graining, and control of geodesics through planarity and increment-stationary last-passage percolation. Joint work with Marton Balazs and Ofer Busani (Bristol).
It turns out that in this new situation, the conclusion changes. Namely, under some conditions, there almost surely exists a (random) "exceptional" set on parameters where the lower limit for the Lyapunov exponent vanishes.
Our results are related to the Anderson localization in dimension one, providing a purely dynamical viewpoint on its proof. I will also speak about some generalizations and related open questions.


== September 19, 2019, [http://math.columbia.edu/~xuanw  Xuan Wu], Columbia University==
== January 30, 2020, Scott Smith (UW Madison) ==
'''TBA'''


'''A Gibbs resampling method for discrete log-gamma line ensemble.'''
== February 6, 2020, Cheuk-Yin Lee (Michigan State) ==
'''TBA'''


In this talk we will construct the discrete log-gamma line ensemble, which is assocaited with inverse gamma polymer model. This log-gamma line ensemble enjoys a random walk Gibbs resampling invariance that follows from the integrable nature of the inverse gamma polymer model via geometric RSK correspondance. By exploiting such resampling invariance, we show the tightness of this log-gamma line ensemble under weak noise scaling. Furthermore, a Gibbs property, as enjoyed by KPZ line ensemble, holds for all subsequential limits.
== February 13, 2020, Jelena Diakonikolas (UW Madison) ==
'''TBA'''


== October 10, 2019, NO SEMINAR - [https://sites.math.northwestern.edu/mwp/ Midwest Probability Colloquium] ==
== February 20, 2020, Philip Matchett Wood (UC Berkeley) ==
'''TBA'''


== October 17, 2019, [https://www.usna.edu/Users/math/hottovy/index.php Scott Hottovy], USNA ==
== February 27, 2020, TBA ==
'''TBA'''


''' Simplified dynamics for noisy systems with delays.'''
== March 5, 2020, Jiaoyang Huang (IAS) ==
'''TBA'''


Many biological and physical systems include some type of random noise with a temporal delay. For example, many sperm cells travel in a random motion where their velocity changes according to a chemical signal. This chemotaxis is transmitted through a delay in the system. That is, the sperm notices chemical gradients after a certain time has elapsed.  In this case, the delay causes the sperm to aggregate around the egg. In this talk I will consider a general stochastic differential delay equation (SDDE) with state-dependent colored noises and derive its limit as the time delays and the correlation times of the noises go to zero. The analysis leads to a much simpler Stochastic Differential Equation to study. The work is motivated by an experiment involving an electrical circuit with noisy, delayed feedback. The main methods used in the proof are a theorem about convergence of solutions of stochastic differential equations by Kurtz and Protter and a maximal inequality for sums of a stationary sequence of random variables by Peligrad and Utev.
== March 12, 2020, TBA ==
'''TBA'''


== October 24, 2019, [https://math.temple.edu/~brider/ Brian Rider], Temple University ==
== March 26, 2020, Philippe Sosoe (Cornell) ==
'''TBA'''


== October 31, 2019, [http://math.mit.edu/~elmos/ Elchanan Mossel], MIT ==
== April 2, 2020, TBA ==
'''TBA'''


== November 7, 2019, [https://people.kth.se/~tobergg/ Tomas Berggren], KTH Stockholm ==
== April 9, 2020, TBA ==
'''TBA'''


== November 14, 2019, [https://math.mit.edu/directory/profile.php?pid=2076 Benjamin Landon], MIT ==
== April 16, 2020, TBA ==
'''TBA'''


== November 21, 2019, TBA ==
== April 22-24, 2020, FRG Integrable Probability meeting ==


== November 28, 2019, Thanksgiving (no seminar) ==


== December 5, 2019, Vadim Gorin, UW Madison ==
== April 30, 2020, Will Perkins (University of Illinois at Chicago) ==
'''TBA'''






<!--


== <span style="color:red"> Wednesday, February 6 at 4:00pm in Van Vleck 911</span> , [https://lc-tsai.github.io/ Li-Cheng Tsai], [https://www.columbia.edu/ Columbia University] ==


Title: '''When particle systems meet PDEs'''


Abstract: Interacting particle systems are models that involve many randomly evolving agents (i.e., particles). These systems are widely used in describing real-world phenomena. In this talk we will walk through three facets of interacting particle systems, namely the law of large numbers, random fluctuations, and large deviations. Within each facet, I will explain how Partial Differential Equations (PDEs) play a role in understanding the systems..


== <span style="color:red">'''Tuesday''' </span>, May 7,  Van Vleck 901, 2:25pm, Duncan Dauvergne (Toronto) ==
<div style="width:250px;height:50px;border:5px solid black">
<b><span style="color:red">&emsp; Please note the unusual day.
&emsp; </span></b>
</div>
Title: '''The directed landscape'''
Abstract: I will describe the construction of the full scaling limit of (Brownian) last passage percolation: the directed landscape. The directed landscape can be thought of as a random scale-invariant `directed' metric on the plane, and last passage paths converge to directed geodesics in this metric. The directed landscape is expected to be a universal scaling limit for general last passage and random growth models (i.e. TASEP, the KPZ equation, the longest increasing subsequence in a random permutation). Joint work with Janosch Ormann and Balint Virag.
-->
== ==


[[Past Seminars]]
[[Past Seminars]]

Revision as of 18:13, 17 January 2020


Spring 2020

Thursdays in 901 Van Vleck Hall at 2:30 PM, unless otherwise noted. We usually end for questions at 3:20 PM.

If you would like to sign up for the email list to receive seminar announcements then please send an email to join-probsem@lists.wisc.edu


January 23, 2020, Timo Seppalainen (UW Madison)

Non-existence of bi-infinite geodesics in the exponential corner growth model

Whether bi-infinite geodesics exist has been a significant open problem in first- and last-passage percolation since the mid-80s. A non-existence proof in the case of directed planar last-passage percolation with exponential weights was posted by Basu, Hoffman and Sly in November 2018. Their proof utilizes estimates from integrable probability. This talk describes an independent proof completed 10 months later that relies on couplings, coarse graining, and control of geodesics through planarity and increment-stationary last-passage percolation. Joint work with Marton Balazs and Ofer Busani (Bristol).

January 30, 2020, Scott Smith (UW Madison)

TBA

February 6, 2020, Cheuk-Yin Lee (Michigan State)

TBA

February 13, 2020, Jelena Diakonikolas (UW Madison)

TBA

February 20, 2020, Philip Matchett Wood (UC Berkeley)

TBA

February 27, 2020, TBA

TBA

March 5, 2020, Jiaoyang Huang (IAS)

TBA

March 12, 2020, TBA

TBA

March 26, 2020, Philippe Sosoe (Cornell)

TBA

April 2, 2020, TBA

TBA

April 9, 2020, TBA

TBA

April 16, 2020, TBA

TBA

April 22-24, 2020, FRG Integrable Probability meeting

April 30, 2020, Will Perkins (University of Illinois at Chicago)

TBA





Past Seminars