10 citations · 24 across the 11 of their papers we have counts for
11 papers
Asymptotic geometric regularity of CAT(0) spaces
Koichi Nagano
We prove that if an n-dimensional geodesically complete CAT(0) space has Tits boundary sufficiently close to the (n-1)-dimensional standard unit sphere, then it is bi-Lipschiz home…
Wall singularity of spaces with an upper curvature bound
Koichi Nagano
We study typical wall singularity of codimension one for locally compact geodesically complete metric spaces with an upper curvature bound. We provide a geometric structure theorem…
Two-dimensional metric spaces with curvature bounded above II
Koichi Nagano, Takashi Shioya, Takao Yamaguchi
As a continuation of \cite{NSY:local}, we mainly discuss the global structure of two-dimensional locally compact geodesically complete metric spaces with curvature bounded above. W…
CAT(0) 4-manifolds are Euclidean
Alexander Lytchak, Koichi Nagano, Stephan Stadler
We prove that a topological 4-manifold of globally non-positive curvature is homeomorphic to Euclidean space.
Asymptotic topological regularity of CAT(0) spaces
Koichi Nagano
We study asymptotic topological regularity of CAT(0) spaces. We prove that if a purely n-dimensional, proper, geodesically complete CAT(0) space has small volume growth, then it is…
Two-dimensional metric spaces with curvature bounded above I
Koichi Nagano, Takashi Shioya, Takao Yamaguchi
We determine the local geometric structure of two-dimensional metric spaces with curvature bounded above as the union of finitely many properly embedded/branched immersed Lipschitz…