English

Manifolds tightly covered by two metric balls

Differential Geometry 2019-02-19 v2

Abstract

In this note we provide natural optimal geometric conditions for a Riemannian manifold suitably covered by two open metric balls to be homeomorphic to a sphere. This can be viewed as a geometric analogue of Brown's theorem in topology stating that a closed manifold covered by two topological balls is a sphere.

Keywords

Cite

@article{arxiv.1610.08190,
  title  = {Manifolds tightly covered by two metric balls},
  author = {Jianming Wan},
  journal= {arXiv preprint arXiv:1610.08190},
  year   = {2019}
}

Comments

With the help of Karsten Grove, the submission is rewirtten. Add two theorems and more connections with previous literatures