Algebraic combinatorics seminar - Mike Zabrocki

Thursday, February 26, 2015 12:00 pm - 12:00 pm EST (GMT -05:00)

Macdonald Symmetric Functions and Parking Functions

Speaker: Mike Zabrocki
Affiliation: York University
Room: Mathematics and Computer Building (MC) 5479

Abstract:

A parking function can be thought of as a Dyck path of length n where the vertical edges are labeled with the integers 1 through n, increasing in the columns. 

Haglund's "shuffle conjecture" from 2005 is a combinatorial formula for the symmetric function expression for $\nabla(e_n)$ with one term for each parking function.  In 2008 Haglund, Morse and myself extended this conjecture to the action of nabla on a symmetric function indexed by a composition. The combinatorial formula has one term for each parking function which touches the diagonal according to the composition.

In the last few years Hicks, Garsia, Xin and myself were partially able to prove the compositional shuffle conjecture by showing algebraic recurrences on coefficients exist and agree with the combinatorics. In this talk I'll show algebraic recurrences which generalize those that were used to prove those results and draws a direct connection with Macdonald symmetric functions.