English

Noncritical maps on geodesically complete spaces with curvature bounded above

Differential Geometry 2024-12-25 v5 Metric Geometry

Abstract

We define and study the regularity of distance maps on geodesically complete spaces with curvature bounded above. We prove that such a regular map is locally a Hurewicz fibration. This regularity can be regarded as a dual concept of Perelman's regularity in the geometry of Alexandrov spaces with curvature bounded below. As a corollary we obtain a sphere theorem for geodesically complete CAT(1) spaces.

Keywords

Cite

@article{arxiv.2107.08859,
  title  = {Noncritical maps on geodesically complete spaces with curvature bounded above},
  author = {Tadashi Fujioka},
  journal= {arXiv preprint arXiv:2107.08859},
  year   = {2024}
}

Comments

Added proofs of Lemmas 3.1 and 3.2, Lemmas 5.3 and 5.4, and other minor changes

R2 v1 2026-06-24T04:19:23.032Z