English

Collapsing and essential coverings

Differential Geometry 2012-05-03 v1

Abstract

In the present paper, we consider the family of all compact Alexandrov spaces with curvature bound below having a definite upper diameter bound of a fixed dimension. We introduce the notion of essential coverings by contractible metric balls, and provide a uniform bound on the numbers of contractible metric balls forming essential coverings of the spaces in the family. In particular, this gives another view for Gromov's Betti number theorem.

Keywords

Cite

@article{arxiv.1205.0441,
  title  = {Collapsing and essential coverings},
  author = {Takao Yamaguchi},
  journal= {arXiv preprint arXiv:1205.0441},
  year   = {2012}
}
R2 v1 2026-06-21T20:57:40.770Z