Mathematical Physics & Dynamical Systems: "Boundary amenability of groups via ultrapowers”
Dr. Isaac Goldbring, UC Irvine
Thursday, June 1, 2017
3:40–5 p.m.
Location: Surge Building 268
Parking Information
Category: Seminar
Description:
A group is said to be boundary amenable if it acts amenably on a compact space. This is a generalization of the notion of amenable group, which is the case that a group acts amenably on a onepoint space. The prototypical example of a group that is boundary amenable but not amenable is the nonabelian free group.
In this talk, we explain how a novel construction of the StoneCech compactification of a space using C*algebra ultraproducts can be used to give a slick proof of the known fact that groups that act properly and isometrically on trees are boundary amenable. We will end with a discussion of how this construction might be useful to settle the boundary amenability of Thompson's group.
Additional Information: Math Seminars
Open to: General Public
Admission: Free
Sponsor: Mathematics
Contact Information:

