Otis Chodosh, Stanford University

Title: Classifying sufficiently connected PSC manifolds in 4 and 5 dimensions

Abstract: I will discuss joint work with C. Li and Y. Liokumovich in which we classify (up to homotopy) 4 dimensional compact manifolds with π2 = 0 that admit Riemannian metrics of positive scalar curvature. Namely, after passing to a finite cover, such a manifold is homotopy equivalent to S4 or a connect sum of S3 x S1's. (The analogous statement holds for 5-dimensional manifolds with π23 =0).