A conformally invariant sphere theorem in four dimensions

2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/68596In 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 figuresDifferential Geometry53C20A conformally invariant sphere theorem in four dimensionstext