Analysis Seminar

Itamar Vigdorovich, Weizmann Institute of Science

"The trace simplex of groups and C*-algebras"

We show that the space of traces of free product C*-algebras C(X)*C(Y), where X and Y are compact perfect spaces, is a Poulsen simplex i.e., the extreme points are dense. This in particular applies to the C*-algebra of the free group C*(Fn). The same statement is true for free products of matrix algebras Mn*Mn, for n at least 4. This answers a question by Musat and Rordam, and relates to quantum factorizable channels. Time permitting, I will discuss strong converses of the above, e.g. in the presence of property (T). The talk is based on a joint work with Orovitz and Slutsky.

This seminar will be held both online and in person:

• Room: MC 5479
• Zoom link: https://uwaterloo.zoom.us/j/94186354814?pwd=NGpLM3B4eWNZckd1aTROcmRreW96QT09