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Geometry-Topology Seminar

Thursday, September 30, 2021 - 5:15pm

Lee Kennard

Syracuse University


University of Pennsylvania


Note that, with the new time schedule for classes, the Geometry-Topology Seminar will continue meeting on Thursdays, but now beginning at 5:15 PM.

In joint work with Michael Wiemeler and Burkhard Wilking at the University of Muenster, we prove optimal estimates on the weighted girth (or systole) of graphs with small first Betti number. By applying results from the theory of regular matroids, this implies results for torus representations having the special property that all isotropy groups are connected. These result in turn imply strong obstructions to the existence of isometric torus actions on positively curved Riemannian manifolds.