Stefaan Vaes: 'Outer actions of amenable groups on von Neumann algebras'

Actions of Tensor Categories on C*-algebras 2021

Mini Course: "Outer actions of amenable groups on von Neumann algebras"
Stefaan Vaes - KU Leuven

Abstract: I will give a survey lecture on the classification of outer actions of amenable groups on von Neumann algebras with the main focus being on II_1 factors. I will introduce the fundamental uniqueness theorem of Ocneanu and his results on vanishing of 2-cohomology. Next, I present more recent work of Sorin Popa on this vanishing of 2-cohomology for actions of amenable groups on arbitrary II_1 factors.

Institute for Pure and Applied Mathematics, UCLA
January 21, 2021