Operator Theory Seminar

Pieter Spaas (UCLA)
Stable decompositions and rigidity for products of countable equivalence relations

After discussing the motivation behind the talk and some necessary preliminaries, we will consider the ''stabilization'' of a countable ergodic p.m.p. equivalence relation which is not Schmidt, i.e., admits no central sequences in its full group. Using a new local characterization of the Schmidt property, we show that this always gives rise to a so-called stable equivalence relation with a unique stable decomposition, providing the first non-strongly ergodic such examples. We will also discuss some new structural results for product equivalence relations, which we will obtain using von Neumann algebraic techniques.

Event Date: 
February 23, 2021 - 1:30pm to 2:20pm
Calendar Category: 
Seminar Category: 
Operator Theory