14.12.21

Cyril Houdayer (Université Paris-Saclay)

Title

Noncommutative ergodic theory of higher rank lattices

Abstract

I will survey recent advances regarding the dynamics of the space of positive definite functions and characters associated with irreducible lattices in higher rank semisimple Lie groups. As I will explain, these results strengthen Margulis’ celebrated normal subgroup theorem and they have several applications to ergodic theory, topological dynamics, unitary representation theory and operator algebras. The key novelty in our approach is a structure theorem for stationary actions of higher rank lattices on (noncommutative) von Neumann algebras. Based on two joint works, the first one with Rémi Boutonnet and the second one with Uri Bader, Rémi Boutonnet, Jesse Peterson. 

Schedule

10:00 - 11:30 RTG Lecture 1 | R. 2.058 | Hybrid

11:30 - 12:00 Get-Together with speaker | R. 2.058 | Hybrid

12:00 - 13:00 Common lunch

13:00 - 13:30 Informal meeting of PhD students | R. 2.058 | Hybrid

13:45 - 14:45 RTG colloquium: Cyril Houdayer | R. 1.067 | Hybrid

14:45 - 15:30 Common tea | R. 1.058

15:30 - 17:00 RTG Lecture 2 | R. 1.067 | Hybrid

KIT