BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Shiyue Li (Brown University) DTSTART:20221208T200000Z DTEND:20221208T210000Z DTSTAMP:20260423T023941Z UID:Matroids/20 DESCRIPTION:Title: K-rings of wonderful varieties and matroids\nby Shiyue Li (Brown Uni versity) as part of Matroids - Combinatorics\, Algebra and Geometry Semina r\n\nLecture held in Room 210 The Fields Institute.\n\nAbstract\nAs we hav e seen in many talks in this wonderful seminar\, the wonderful variety of a realizable matroid and its Chow ring have played key roles in solving ma ny long-standing open questions in combinatorics and algebraic geometry. Y et\, its $K$-rings are underexplored until recently. I will be sharing wit h you some discoveries on the $K$-rings of the wonderful variety associate d with a realizable matroid: an exceptional isomorphism between the $K$-ri ng and the Chow ring\, with integral coefficients\, and a Hirzebruch–Rie mann–Roch-type formula. These generalize a recent construction of Berget –Eur–Spink–Tseng on the permutohedral variety. We also compute the E uler characteristic of every line bundle on wonderful varieties\, and give a purely combinatorial formula. This in turn gives a new valuative invari ant of an arbitrary matroid. As an application\, we present the $K$-rings and compute the Euler characteristic of arbitrary line bundles of the Deli gne–Mumford–Knudsen moduli spaces of rational stable curves with disti nct marked points. Joint with Matt Larson\, Sam Payne and Nick Proudfoot.\ n LOCATION:https://researchseminars.org/talk/Matroids/20/ END:VEVENT END:VCALENDAR