Date | Time | Speaker | Title | Cookies, dinner, etc. |

Tuesday, September 23 | 4:00 p.m. | Turbo Ho, UW | Random nilpotent groups (see abstract) | cookies/ beverages at 3:30 |

Tuesday, September 30 (Midwest Computability Seminar, University of Chicago)
| 1:00 p.m. | Eric Astor, University of Chicago, Illinois | TBA | depart at 8:30 a.m. from Van Vleck loading dock/ lunch at noon in Ryerson/ dinner at 6 TBA |

1:35 p.m. | Quinn Culver, University of Notre Dame, Indiana | TBA | ||

2:30 p.m. | Jack Lutz, Iowa State University, Ames | TBA | ||

4:10 p.m. | Tim McNicholl, Iowa State University, Ames | TBA | ||

Sunday, October 5
| 1:20 p.m. | Wim Ruitenburg, Marquette University, Milwaukee, Wisconsin | From Boole to Heyting to Visser, and beyond | lunch at noon TBA |

2:00 p.m. | Patricia Blanchette, University of Notre Dame | The birth of semantic entailment | ||

3:20 p.m. | Jon Fleischmann, University of Wisconsin-Rock County, Janesville | U_{2}-sentences and chains of Kripke models
(see abstract)
| ||

4:20 p.m. | Tom Drucker, University of Wisconsin-Whitewater | Hijacking Leibniz: What non-standard analysis cannot do | ||

Tuesday, October 14 | 4:00 p.m. | Jim Freitag, University of California-Berkeley | TBA | cookies/ beverages at 3:30/ dinner at 6 TBA |

Tuesday, October 21 | 4:00 p.m. | Howard Becker, UW | TBA | cookies/ beverages at 3:30 |

Tuesday, October 28 (Midwest Model Theory Day, University of Illinois at Chicago)
| 1:00 p.m. | Ward Henson, University of Illinois at Urbana-Champaign | TBA | depart at 8:30 a.m. from Van Vleck loading dock/ lunch at 11:30 at Joy Yee's (1335 S. Halsted)/ dinner at 5:30 TBA |

2:30 p.m. | Krzysztof Krupiński, University of Wrocław, Poland | TBA | ||

4:00 p.m. | Ramin Takloo-Bighash, University of Illinois-Chicago | TBA | ||

Tuesday, November 11 | 4:00 p.m. | Reese Johnston, UW | TBA (specialty exam) | cookies/ beverages at 3:30 |

**Course Description:**
This course will serve as a survey of historical and current research in
computable model theory. There will be a focus on recursive model theory
and the model theory of models of Peano Arithmetic.

We establish results about the distribution of rank and step for random
nilpotent groups. We compute probabilities for random one-relator quotients
of N_{p,m} to be abelian, and we show that for any number of relators,
random quotients of N_{2,m} are almost never abelian but not cyclic.

Finally, we describe how to lift results about random nilpotent groups to obtain information about standard random groups. A random nilpotent group is trivial if and only if the corresponding random group is perfect, i.e., is equal to its commutator subgroup. Considering adding relators one by one in a stochastic process, we study the threshold number of relators required. This threshold occurs at |R| = log l, while the expected number of relators required is |R| = log log l. As a corollary, at any positive density, random groups are perfect.

This is joint work with Matt Cordes, Moon Duchin, Yen Duong, and Andrew Sanchez.

This research is joint work with Wim Ruitenburg, Ben Ellison, and Dan McGinn.

Prepared by Steffen Lempp (@math.wisc.edu">lemppmath.wisc.edu)