# Per Alexandersson: The Schur expansion of skew specialized Macdonald polynomials

**Time: **
Wed 2019-06-05 10.15 - 11.00

**Location: **
Room 3418, Lindstedtsvägen 25. Department of Mathematics, KTH

**Participating: **
Per Alexandersson

Abstract: We use a variant of RSK to give the Schur expansion of a

certain generalization of Macdonald polynomials.This family is closely related to LLT polynomials, for which there is

still no combinatorial proof of Schur positivity.

If there is time, we also give a new positive formula for

Touchard-Riordan polynomials, which reveals a surprising connection with rook-theory and acyclic

orientations of unit-interval graphs.

This is joint work with Joakim Uhlin.