Modul: MAT760 Ergodic theory and dynamical systems seminar

## Higher rank rigidity and discrete subgroups of semisimple Lie groups

Talk by Dr. Mikolaj Fraczyk

Speaker invited by: Prof. Dr. Alexander Gorodnik

**Date:** 22.05.24 **Time:** 13.30 - 14.30 **Room:** ETH HG G 19.1

I will talk about a new strategy of studying discrete subgroup of a higher rank semisimple Lie group using the high and low entropy methods for actions of higher rank abelian groups. They were developed by Einsiedler-Katok-Lindenstrauss to study A-invariant measures on (typically finite volume) quotients of semisimple Lie groups. The properties of such measures can reveal a lot about the geometry of the quotient, wich in turn makes them a useful tool in studying (a priori) infinite covolume subgroups of semisimple Lie groups. Based on a joint work with Minju Lee.''