English

$\mathrm{RCD}^{*}(K,N)$ spaces are semi-locally simply connected

Differential Geometry 2022-11-15 v1

Abstract

It was shown by Mondino-Wei that any RCD(K,N)\mathrm{RCD}^{*}(K,N) space (X,d,m)(X,d,\mathfrak{m}) has a universal cover. We prove that for any point xXx \in X and R>0R>0, there exists r<Rr<R such that any loop in Br(x)B_r(x) is contractible in BR(x)B_R(x); in particular, XX is semi-locally simply connected and the universal cover of XX is simply connected. This generalizes the author's earlier work that any Ricci limit space is semi-locally simply connected.

Keywords

Cite

@article{arxiv.2211.07087,
  title  = {$\mathrm{RCD}^{*}(K,N)$ spaces are semi-locally simply connected},
  author = {Jikang Wang},
  journal= {arXiv preprint arXiv:2211.07087},
  year   = {2022}
}