EVENT DETAILS AND ABSTRACT

Title: Shift-minimal groups, fixed price 1, and the unique trace property
Speaker: Robin Tucker-Drob
Speaker Info:
Brief Description:
Special Note: Note special time
Abstract:

A countable group G is called shift-minimal if all non-trivial measure preserving actions weakly contained in the Bernoulli shift of G are free. I will discuss the connection between shift-minimality, cost, and properties of the reduced C*-algebra of G, indicating the proof that if G admits a free measure preserving action of cost strictly greater than 1 then there is a finite normal subgroup N of G such that G/N is shift-minimal. I will also discuss some open problems suggested by these results which concern reduced C*-algebras of groups with positive first l^2 Betti number.