English

A note on ANR's

General Topology 2014-11-03 v2

Abstract

It is shown that if for a complete metric space (X,d)(X,d) there is a constant ϵ>0\epsilon > 0 such that the intersection j=1nBd(xj,rj)\bigcap_{j=1}^n B_d(x_j,r_j) of open balls is nonempty for every finite system x1,...,xnXx_1,...,x_n \in X of centers and a corresponding system of radii r1,...,rn>0r_1,...,r_n > 0 such that d(xj,xk)\leqslϵd(x_j,x_k) \leqsl \epsilon and d(xj,xk)<rj+rkd(x_j,x_k) < r_j + r_k (j,k=1,...,nj,k = 1,...,n), then XX is an ANR; and if in the above one may put ϵ=\epsilon = \infty, the space XX is an AR. A certain criterion for an incomplete metric space to be an A(N)R is presented.

Cite

@article{arxiv.1107.1508,
  title  = {A note on ANR's},
  author = {Piotr Niemiec},
  journal= {arXiv preprint arXiv:1107.1508},
  year   = {2014}
}

Comments

The paper has been withdrawn by the author because of its publication in Topology Appl

R2 v1 2026-06-21T18:33:47.088Z