Geometry, Topology and Dynamics Seminar
Nir Avni
Hebrew University, Jerusalem
Entropy theory for cross sections
Abstract: A theorem of Kolmogorov states that if a probability preserving
automorphism T is completely positive entropy (this means that for every
nontrivial partition P, h(T,P)>0) then T is uniformly mixing and its spectrum
is Lebesgue with countable multiplicity. I will describe a generalization of
this theorem to probability preserving actions of a large class of amenable
groups.
As a tool for the proof, an entropy theory for cross sections is developed.
Wednesday November 30, 2005 at 3:00 PM in SEO 427