Geometry Seminar
Winter 2021
Thursdays (and sometimes Tuesdays) 3:404:30pm, in
Ryerson 358 (currently on zoom)

 Thursday January 21 at 3:404:30pm in Zoom
 Kevin Schreve, University of Chicago
 Invariant random subgroups

Abstract: This talk is intended to provide some
background for Mikolaj Fraczyk's talk next week. I will
introduce the Chabauty topology, BenjaminiSchramm
convergence, and invariant random subgroups.

 Thursday January 28 at 3:404:30pm in Zoom
 Mikolaj Fraczyk, University of Chicago
 Injectivity radius of discrete subgroups of higher rank groups

Abstract: Let G be a simple higher rank Lie group
and let X be the associated symmetric space. Margulis
conjectured that any discrete subgroup Gamma of G such that
X/Gamma has uniformly bounded injectivity radius must be a
lattice. I will present the proof of this conjecture and
explain how stationary random subgroups play the central
role in the argument. The talk will be based on a recent
joint work with Tsachik Gelander.

 Thursday February 4 at 3:404:30pm in Zoom
 Kasia Jankiewicz, University of Chicago
 TBA

Abstract: TBA

 Thursday February 11 at 3:404:30pm in Zoom
 Alexander Olshanskiy, Vanderbilt University
 TBA

Abstract: TBA

 Thursday February 18 at 3:404:30pm in Zoom
 Danny Calegari, University of Chicago
 TBA

Abstract: TBA

 Thursday February 25 at 3:404:30pm in Zoom
 Daniil Rudenko, University of Chicago
 TBA

Abstract: TBA
Due to the high number of requests, we are no longer accepting speakers via selfinvitations.
For questions, contact