# Topological Sphere Theorem

Date:

Monday, 8 July, 2019 - 09:30 - 10:30

Venue:

LSB 222

Seminar Type:

Career Talk

Speaker Name:

Mr. Tin Yau TSANG

Affiliation:

University of California, Irvine

Abstract:

These talks are an introduction of a classical global geometry theorem - the sphere theorem which states that a compact simply connected manifold with quarter pinching is homeomorphic to a sphere. This was proved in 60's by Klingenberg’s estimate for cut locus and Berger’s use of Toponogov’s theorem. Hence, we would begin by reviewing curvature and geodesic. Then we will prove Toponogov’s theorem and apply it to prove the sphere theorem.

Poster: