Outer Actions of Amenable Groups on von Neumann Algebras

Explore a comprehensive survey lecture on the classification of outer actions of amenable groups on von Neumann algebras, with a primary focus on II_1 factors. Delve into Ocneanu's fundamental uniqueness theorem and his results on vanishing 2-cohomology. Discover more recent work by Sorin Popa on the vanishing of 2-cohomology for actions of amenable groups on arbitrary II_1 factors. Gain insights into this advanced topic in mathematical physics through this 47-minute presentation delivered by Stefaan Vaes from KU Leuven as part of the "Actions of Tensor Categories on C*-algebras 2021" mini-course at the Institute for Pure & Applied Mathematics (IPAM), UCLA.