A conformally invariant sphere theorem in four dimensions

Chang, S. Y. A; Gursky, Matthew J.; Yang, Paul

A conformally invariant sphere theorem in four dimensions

Authors

Chang, S. Y. A

Gursky, Matthew J.

Yang, Paul

Description

In this paper we provide a sharp characterization of the smooth four-dimensional sphere. The assumptions of the theorem are conformally invariant, and can be reduced to an L^2 inequality of the Weyl tensor and positivity of the Yamabe invariant.
39 pages, 0 figures