## Discrete Math Seminar: Jair Taylor

• Date: 09/22/2015
• Time: 16:00
Lecturer(s):
Jair Taylor, University of Washington
Location:

University of British Columbia

Topic:

Chromatic symmetric functions of hypertrees

Description:

The chromatic symmetric function $X_H$ of a hypergraph $H$ is the generating function for all colorings of $H$ so that no edge is monochromatic. When $H$ is an ordinary graph, it is known that $X_H$ is positive in the fundamental quasisymmetric functions $F_S$, but this is not the case for general hypergraphs. We exhibit a class of hypergraphs $H$ --- hypertrees with prime-sized edges --- for which $X_H$ is $F$-positive, and give an explicit combinatorial interpretation for the $F$-coefficients of $X_H$.  We also present a conjecture that certain chromatic symmetric functions of hypergraphs are Schur-positive.

Other Information:

Location: ESB 4127