Metric limits of manifolds with positive scalar curvature

Abstract

We show that any Riemannian metric conformal to the round metric on $S^n$, for $n\ge 4$, arises as a limit of a sequence of Riemannian metrics of positive scalar curvature on $S^n$ in the sense of uniform convergence of Riemannian distance. In particular, non-negativity of scalar curvature is not preserved under such limits.

To appear in the American Journal of Mathematics