Groups and Dynamics Seminar

Date: December 1, 2021

Time: 3:00PM - 4:00PM

Location: online

Speaker: Matthieu Joseph, Ecole Normale Superieure, Lyon

Title: Allosteric actions of surface groups

Abstract: In a recent work, I introduced the notion of allosteric actions: a minimal action of a countable group on a compact space, with an ergodic invariant measure, is allosteric if it is topologically free but not essentially free. In the first part of my talk I will explain some properties of allosteric actions, and their links with Invariant Random Subgroups (IRS) and Uniformly Recurrent Subgroups (URS). In the second part, I will explain a recent result of mine: the fundamental group of a closed hyperbolic surface admits allosteric actions.