Counting open negatively curved manifolds up to tangential homotopy equivalence
arXiv:math/9809014
Abstract
Under mild assumptions on a group G, we prove that the class of complete Riemannian n-manifolds of uniformly bounded negative sectional curvatures and with the fundamental groups isomorphic to G breaks into finitely many tangential homotopy types. It follows that many aspherical manifolds do not admit complete negatively curved metrics with prescribed curvature bounds.
22 pages, no figures; to appear in Journal of Differential Geometry