Pure Math Colloquium

Sven Raum, Stockholm University

"Superrigidity for group operator algebras"

It is a classical problem to recover a discrete group from various rings or algebras associated with it, such as the integral group ring. By analogy, in an operator algebraic framework we want to recover torsion-free groups from certain topological completions of the complex group ring, such as the reduced group C*-algebra. Groups for which this is possible are called C*-superrigid.

I will start this talk with a discussion of how a group can be recovered from its group rings, before I introduce the reduced group C*-algebras and describe the state-of-the-art in C*-superrigidity. I will end with a short account on other kinds of superrigidity for group operator algebras putting the subject into a bigger perspective.

MC 5501