**SMS scnews item created by Stephan Tillmann at Thu 9 Oct 2014 1020**

Type: Seminar

Distribution: World

Expiry: 8 Jan 2015

**Calendar1: 29 Oct 2014 1100-1200**

**CalLoc1: Carslaw 535A**

Auth: tillmann@p710.pc (assumed)

### Geometry-Topology-Analysis Seminar

# Ergodic theorems for amenable groups

### Sasha Fish (Sydney)

GTA Seminar - Wednesday, 29 October, 11:00-12:00 in Carlaw 535A

##
Ergodic theorems for amenable groups

We will talk on the validity of the mean ergodic theorem along
left Følner
sequences in a countable amenable group G. Although the weak ergodic theorem
always holds
along any left Følner sequence in G, we will provide examples where the mean
ergodic theorem fails
in quite dramatic ways. On the other hand, if G does not admit any ICC
quotients, e.g. if G is
virtually nilpotent, then we will prove that the mean ergodic theorem does
indeed hold along any left
Følner sequence.
Based on the joint work with M. Bjorklund (Chalmers).

Please join us for lunch after the talk!