Manifolds with 2-nonnegative Ricci operator

Martha P. Dussan and Maria Helena Noronha

Vol. 204 (2002), No. 2, 319–334

DOI: 10.2140/pjm.2002.204.319

Abstract

In this paper we study compact manifolds with 2-nonnegative Ricci operator, assuming that their Weyl operator satisfies certain conditions which generalize conformal flatness. As a consequence, we obtain that such manifolds are either locally symmetric or their Betti numbers between 2 and n − 2 vanish. We also study the topology of compact hypersurfaces with 2-nonnegative Ricci operator.

Milestones

Received: 29 September 2000

Revised: 26 March 2001

Published: 1 June 2002