arXiv · 2109.09438
We prove that a topological 4-manifold of globally non-positive curvature is homeomorphic to Euclidean space.
Alexander Lytchak, Koichi Nagano, Stephan Stadler. 2021-09-20. CAT(0) 4-manifolds are Euclidean. https://arxiv.org/abs/2109.09438
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