题目：Positive curvature and torus representations with connected isotropy groups .

报告人：Lee Kennard教授, 美国雪城大学

Abstract : A 1930s conjecture of Hopf states that an even-dimensional Riemannian manifold with positive sectional curvature has positive Euler characteristic. In joint work with Michael Wiemeler and Burkhard Wilking, this conjecture is confirmed under the additional assumption that the isometry group has rank at least five. Similar previous results required bounds on the rank that grew to infinity in the manifold dimension. The main new tool is a structural result for representations of tori with the special property that all isotropy groups are connected. Such representations are surprisingly rigid, and we analyze them using only elementary techniques. A full classification of such representations remains an open problem.

时间： 5月30日（周四）上午10:30-11:30

地点：565net必赢客户端本部教二楼 827 教室

联系人：戎小春

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