Seminar (Operator Algebras)

Ado Dalla Costa (Universidade Federal de Santa Catalina)

Free actions of groups on separated graphs and their associated C*-algebras

Abstract: I will report on joint work with Alcides Buss and Pere Ara on the study of free actions of groups on separated graphs and explain how this structure reflects on the level of their associated C*-algebras. We prove a version of the Gross-Tucker theorem in this context and show how this can be used to describe the various C*-algebras attached to separated graphs carrying a free action. All this leads to certain Landstad-type duality theorems involving these algebras.