# Events for 02/26/2021 from all calendars

## Noncommutative Geometry Seminar

**Time: ** 1:00PM - 2:00PM

**Location: ** Zoom 951 5490 42

**Speaker: **Alcides Buss, Universidade Federal de Sanata Catarina

**Title: ***Amenable actions of groups on C*-algebras*

**Abstract: **In this lecture I will explain recent developments in the theory of amenability for actions of groups on C*-algebras and Fell bundles, based on joint works with Siegfried Echterhoff, Rufus Willett, Fernando Abadie and Damian Ferraro. Our main results prove that essentially all known notions of amenability are equivalent. We also extend Matsumura’s theorem to actions of exact locally compact groups on commutative C*-algebras and give a counter-example for the weak containment problem for actions on noncommutative C*-algebras.

**URL: ***Event link*

## Algebra and Combinatorics Seminar

**Time: ** 3:00PM - 4:00PM

**Location: ** Zoom

**Speaker: **He Guo, Georgia Tech

**Title: ***Prague dimension of random graphs*

**Abstract: **The Prague dimension of graphs was introduced by Nesetril, Pultr and Rodl in the 1970s. Proving a conjecture of Furedi and Kantor, we show that the Prague dimension of the binomial random graph is typically of order n/log n for constant edge-probabilities. The main new proof ingredient is a Pippenger-Spencer type edge-coloring result for random hypergraphs with large uniformities, i.e., edges of size O(log n).
Based on joint work with Kalen Patton and Lutz Warnke.