Stuart White

(updated) Quasidiagonality and amenability

(updated) Amenability is one of the central concepts of group theory, touching pretty much every place where analysis meets groups, and is somewhat measurable in nature. Quasidiagonality is an approximation property, originating in work of Halmos in operator theory, and it turns out to be topological in nature. I’ll discuss these properties, and how they are related through a conjecture of Rosenberg. All background will be supplied (beyond the definition of bounded operators on a Hilbert space).