Much of modern dynamics is rephrased in the language of group actions and representation theory. A measure-preserving group action on some space gives rise to a unitary representation of that group. Hence dynamics leads to studying unitary representations of infinite groups. The space of all unitary representations of a topological group can be given a natural topology called the Fell topology. Equipped with the definition of this topology, one may rigorously define several of the key concepts in the field: weak containment of representations, amenability, property T, Plancherel measure, etc. In this talk we'll motivate and define these concepts and illuminate them through concrete examples.

Zoom link: https://umich.zoom.us/j/99788564257
passcode: -4040 Speaker(s): Carsten Peterson (University of Michigan)