## Geometry & Representation - John Michael Machacek (York University)

### Monday, October 7th, 2019

**Time:** 4:30-5:30 p.m. **Place:** Jeffery Hall 319

**Speaker:** John Michael Machacek (York University)

**Title:** Mutation combinatorics and upper cluster algebras.

**Abstract: ** Any cluster algebra is contained in an intersection of Laurent polynomial rings known as its upper cluster algebra. There are known cases where this containment is equality as well as cases of strict containment. We will discuss combinatorial approaches to determining if this containment is strict or not. Notions used will include reddening sequences and locally acyclic cluster algebras.