BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Jun-Muk Hwang (Korea Institute for Advanced Study) DTSTART:20211207T100000Z DTEND:20211207T110000Z DTSTAMP:20260423T021418Z UID:ZAG/170 DESCRIPTION:Title: Mi nimal rational curves and 1-flat irreducible G-structures\nby Jun-Muk Hwang (Korea Institute for Advanced Study) as part of ZAG (Zoom Algebraic Geometry) seminar\n\n\nAbstract\n1-flat irreducible G-structures\, equiva lently\, irreducible G-structures admitting torsion-free affine connection s\, have been studied extensively in differential geometry\, especially i n connection with the theory of affine holonomy groups. In a joint work wi th Qifeng Li\, we study them in a setting in algebraic geometry\, where th ey arise from varieties of minimal rational tangents (VMRT) associated to families of minimal rational curves on uniruled projective manifolds. We p rove that such a structure is locally symmetric when the dimension of the uniruled projective manifold is at least 5. By the classification result o f Merkulov and Schwachhoefer on irreducible affine holonomy\, the problem is reduced to the case when the VMRT at a general point of the uniruled pr ojective manifold is isomorphic to a subadjoint variety. In the latter sit uation\, we prove a stronger result that\, without the assumption of 1-fla tness\, the structure arising from VMRT is always locally flat.\n LOCATION:https://researchseminars.org/talk/ZAG/170/ END:VEVENT END:VCALENDAR