Combinatorial statistics and the q,t-Catalan numbers

Spencer Daugherty, University of Colorado Boulder
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PDL C-401 and via Zoom Link: https://washington.zoom.us/j/91547335974

Abstract:

The \$q,t\$-Catalan numbers can be described elegantly in terms of pairs of statistics on Dyck paths: area and bounce, or area and dinv. Using bijective and recursive methods, we prove new expressions of the \$q,t\$-Catalan numbers in terms of pairs of statistics on other Catalan objects such as subsets of permutations, noncrossing partitions, unit interval orders, and certain Young tableaux. Special attention will be given to two different formulations using the disorder statistic on permutations. We also study the relationship of our statistics with the zeta map on Dyck paths and discuss implications for the \$q,t\$-Catalan symmetry problem.

Note: This talk begins with a pre-seminar (aimed at graduate students) at 3:30–4:00. The main talk starts at 4:10.

Join Zoom Meeting: https://washington.zoom.us/j/91547335974
Meeting ID: 915 4733 5974