math.DG — Differential Geometry
A contractible open four-manifold with a complete metric of uniformly positive scalar curvature
We construct a smooth contractible open four-manifold that is not homeomorphic to and admits a complete Riemannian metric with scalar curvature at least one. This gives a negative answer to a question raised by Chang--Weinberger--Yu and Chodosh--M\'aximo--Mukherjee.
A mix of human-written and AI-generated textHuman understanding: all partsBaumslag–Solitar groupsGromov–Lawson surgerycontractible four-manifoldsgeometric topologyopen four-manifoldspositive scalar curvaturetopology at infinity