Wednesday, November 28, 2018 at 4:15pm to 5:15pm
SPEAKER: Lauren Williams (Harvard University)
TITLE: From multiline queues to Macdonald polynomials via the exclusion process
Recently James Martin introduced multiline queues, and used them to give a combinatorial formula for the stationary distribution of the multispecies asymmetric simple exclusion exclusion process (ASEP) on a circle. The ASEP is a model of particles hopping on a one-dimensional lattice, which was introduced around 1970, and has been extensively studied in statistical mechanics, probability, and combinatorics. In this article we give an independent proof of Martin's result, and we show that by introducing additional statistics on multiline queues, we can use them to give a new combinatorial formula for both the symmetric Macdonald polynomials Pλ(x; q, t), and the nonsymmetric Macdonald polynomials Eλ(x; q, t), where lambda is a partition. This formula is rather different from others that have appeared in the literature, such as the Haglund-Haiman-Loehr formula. Our proof uses results of Cantini-de Gier-Wheeler, who recently linked the multispecies ASEP on a circle to Macdonald polynomials.