## Colloquium - Ying Anna Pun

**Date: ** January 28, 2022

**Time: ** 4:00PM - 5:00PM

**Location: ** BLOC 117

**Speaker: **Ying Anna Pun, University of Virginia

**Description: ****Title:** Symmetric functions -- a gem in algebraic combinatorics
**Abstract:** Algebraic combinatorics is a subject that interprets algebraic objects combinatorically and combinatorial objects algebraically, thereby obtaining deep connections between the two areas. The study of
polynomial rings is one of the important topics in algebraic combinatorics, as the associated combinatorial tools provide profound connections with partitions of integers and the representation theory
of the symmetric group, the general linear group, Lie algebra, Hecke algebras, elliptic Hall algebra, shuffle algebra and other important algebras. It also gives fruitful information on objects in algebraic geometry such as the multiplicative structure of the cohomology ring of the Grassmannian.
In this talk, I will introduce the ring of symmetric functions and discuss some important bases and their associated combinatorial objects. I will then discuss some conjectures and theorems in algebraic combinatorics that are inspired by the Macdonald positivity conjecture and end with a brief introduction to Catalanimals, an exciting powerful tool to prove these theorems.