Positive scalar curvature metric and aspherical summands

Fri Nov 17, 2023 2:00 p.m.—3:00 p.m.
Exterior of Sheffield-Sterling-Strathcona Hall featuring a stone carving of Yale's coat of arms and motto

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Seminar: 
Geometric Analysis and Application

Event time: 
Friday, November 17, 2023 - 2:00pm

Location: 
KT 906

Speaker: 
Shuli Chen

Speaker affiliation: 
Stanford University

Event description: 
Abstract: It has been a classical question which manifolds admit Riemannian metrics with positive scalar curvature. A manifold is called aspherical if it has contractible universal cover. By works of Chodosh—Li, Gromov, and Chodosh—Li—Liokumovich, for n = 4, 5, the connected sum of a closed aspherical n-manifold with an arbitrary closed manifold does not admit a metric with positive scalar curvature. We prove that for n = 3,4,5, the connected sum of a closed aspherical n-manifold with an arbitrary non-compact manifold does not admit a complete metric with nonnegative scalar curvature. In particular, a special case of our result answers a question of Gromov. This is joint work with Jianchun Chu and Jintian Zhu.