##### Department of Mathematics,

University of California San Diego

****************************

### Math 269 - Combinatorics

## Michelle Wachs

#### University of Miam

## Eulerian numbers, chromatic quasisymmetric functions and Hessenberg varieties

##### Abstract:

We consider three distinct topics of independent interest; one in enumerative combinatorics, one in symmetric function theory, and one in algebraic geometry. The topic in enumerative combinatorics concerns a q-analog of a generalization of the Eulerian numbers, the one in symmetric function theory deals with a refinement of Stanley's chromatic symmetric functions, and the one in algebraic geometry deals with a representation of the symmetric group on the cohomology of the regular semisimple Hessenberg variety of type A. Our purpose is to explore some connections between these topics and consequences of these connections. This talk is based on joint work with John Shareshian.

Host: Jeff Remmel

### December 17, 2013

### 3:00 PM

### AP&M 7321

****************************