Half-way seminar, Paolo Boldrini

Abstract: Dynamical comparison is a property of group actions that received significant attention in the last few years due to its connection with the problem of classification of crossed product C*-algebras by the Elliott invariant. Since its first appearance, dynamical comparison has been verified for a wide variety of actions. In joint work with Akshara Prasad, we constructed the first examples of topologically free minimal actions that fail dynamical comparison, and we showed that this phenomenon can occur both in the presence and in the absence of invariant measures.