BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Lorenzo Vecchi (Università di Bologna) DTSTART:20221020T141500Z DTEND:20221020T160000Z DTSTAMP:20260422T065719Z UID:CJCS/90 DESCRIPTION:Title: Sk ew Young Tableaux for KL polynomials of matroids\nby Lorenzo Vecchi (U niversità di Bologna) as part of Copenhagen-Jerusalem Combinatorics Semin ar\n\n\nAbstract\nKazhdan-Lusztig polynomials of matroids were first intro duced in 2016 in analogy with the classical ones for the Bruhat order in C oxeter groups.\nIn 2020 it was proved that their coefficients are always n on-negative\, by interpreting them as the Hilbert series of the local inte rsection cohomology of some modules associated to the matroid\; however\, since these polynomials can be completely characterized only using the lat tice of flats\, a combinatorialist wonders if any result about them can be reobtained exploiting no algebraic geometry results.\nAfter introducing t he operation of stressed hyperplane relaxation\, we show that we can compu te these coefficients by counting fillings of special skew tableaux shapes . We will also show how these results can be interpreted using representat ion theory on the group of automorphisms of the matroid.\nThis is joint wo rk with Luis Ferroni and George Nasr\, and Trevor Karn\, George Nasr and N icholas Proudfoot.\n LOCATION:https://researchseminars.org/talk/CJCS/90/ END:VEVENT END:VCALENDAR