Classifying sufficiently connected PSC manifolds in $4$ and $5$ dimensions

Abstract

We show that if $N$ is a closed manifold of dimension $n=4$ (resp. $n=5$) with ${\pi }_2(N)=0$ (resp. ${\pi }_2(N)={\pi }_3(N)=0$) that admits a metric of positive scalar curvature, then a finite cover $\hat{N}$ of $N$ is homotopy equivalent to $S^n$ or connected sums of $S^{n-1}\times S^1$. Our approach combines recent advances in the study of positive scalar curvature with a novel argument of Alpert--Balitskiy--Guth. Additionally, we prove a more general mapping version of this result. In particular, this implies that if $N$ is a closed manifold of dimensions $4$ or $5$, and $N$ admits a map of nonzero degree to a closed aspherical manifold, then $N$ does not admit any Riemannian metric with positive scalar curvature.

To appear in Geom. Topol

References in corpus (1)

• No metrics with Positive Scalar Curvatures on Aspherical 5-Manifolds

Cited by in corpus (3)

• Nonnegative scalar curvature on manifolds with at least two ends
• The positive mass theorem and distance estimates in the spin setting
• Rigidity and Non-Rigidity of ${\mathbb{H}}^n/{\mathbb{Z}}^{n-2}$ with Scalar Curvature Bounded from Below