BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Claire Voisin (Collège de France) DTSTART:20200618T140000Z DTEND:20200618T150000Z DTSTAMP:20260423T021448Z UID:ZAG/24 DESCRIPTION:Title: Tri angle varieties and surface decomposition of hyper-Kahler manifolds\nb y Claire Voisin (Collège de France) as part of ZAG (Zoom Algebraic Geomet ry) seminar\n\n\nAbstract\nIn recent years\, new constructions of complete families of polarized hyper-Kahler manifolds have been found starting fro m Fano geometry. These hyper-Kahler manifolds also appear as general defor mations of Hilbert schemes of K3 surfaces or O'Grady manifolds. I will int roduce the notion of surface decomposition for a variety X with a nontrivi al Hodge structure on degree 2 cohomology. I will show that this notion is restrictive topologically\, as it implies Beauville-Fujiki type relations . I will also show the existence of such a surface decomposition for the general hyper-Kahler manifolds mentioned above. This has interesting co nsequences on Beauville's conjecture on the Chow ring of hyper-Kahler mani folds.\n LOCATION:https://researchseminars.org/talk/ZAG/24/ END:VEVENT END:VCALENDAR