2026/07/27 by Jiangcheng You, Heng Zhang
#math.DG
We prove that a contractible 3-manifold admitting a complete Riemannian metric of nonnegative scalar curvature is diffeomorphic to \R3. We also prove that, if the interior Mγ of a compact handlebody of genus γ admits such a metric, then γ≤1. This answers two open questions posed by Wang and Gromov, respectively.