4 papers
Busemann G-spaces with convex balls
Tadashi Fujioka, Shijie Gu
We prove that any Busemann G-space such that every sufficiently small metric ball is convex is a topological manifold. The key ingredient in the proof is Ivanov's Helly theorem. Th…
Finsler structure of Busemann G-spaces
Tadashi Fujioka, Shijie Gu
We provide two sufficient conditions for a Busemann G-space to admit a differentiable DC atlas with a continuous Finsler metric, from the viewpoint of comparison geometry. These re…
Busemann and MCP
Tadashi Fujioka, Kenshiro Tashiro
We study the structure of Busemann spaces with measures satisfying the measure contraction property (MCP). The main results are rigidity theorems and structure theorems under the a…
Topological regularity of Busemann spaces of nonpositive curvature
Tadashi Fujioka, Shijie Gu
We extend the topological results of Lytchak-Nagano and Lytchak-Nagano-Stadler for CAT(0) spaces to the setting of Busemann spaces of nonpositive curvature, i.e., BNPC spaces. We g…