April 19, 2024
On Cartan subalgebras of $II_1$ factors arising from Bernoulli actions of weakly amenable groups- Location – SC1432
A conjecture of Popa states that the $II_1$ factor arising from a Bernoulli action of a nonamenable group has a unique (group measure space) Cartan subalgebra, up to unitary conjugacy. In this talk, I will discuss this conjecture and show that it holds for weakly amenable groups with constant $1$ among algebraic actions. The proof involves the notion of properly proximal groups introduced by Boutonnet, Ioana, and Peterson.