BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Yalong Cao DTSTART:20220519T080000Z DTEND:20220519T090000Z DTSTAMP:20260423T021727Z UID:HubEG/4 DESCRIPTION:Title: Go pakumar-Vafa type invariants of holomorphic symplectic 4-folds\nby Yal ong Cao as part of Events Hub: Enumerative geometry\n\n\nAbstract\nAbstrac t: Gromov-Witten invariants of holomorphic symplectic 4-folds vanish and o ne can consider the corresponding reduced theory. In this talk\, we will e xplain a definition of Gopakumar-Vafa type invariants for such a reduced t heory. These invariants are conjectured to be integers and have alternativ e interpretations using sheaf theoretic moduli spaces. Our conjecture is p roved for the product of two K3 surfaces\, which naturally leads to a clos ed formula of Fujiki constants of Chern classes of tangent bundles of Hilb ert schemes of points on K3 surfaces. On a very general holomorphic symple ctic 4-folds of K3^[2] type\, our conjecture provides a Yau-Zaslow type fo rmula for the number of isolated genus 2 curves of minimal degree. Based o n joint works with Georg Oberdieck and Yukinobu Toda.\n\nZoom Meeting ID: 271 534 5558\nPasscode: YMSC\n LOCATION:https://researchseminars.org/talk/HubEG/4/ END:VEVENT END:VCALENDAR