English

Spaces which invert weak homotopy equivalences

Algebraic Topology 2019-04-10 v1

Abstract

It is well known that if XX is a CW-complex, then for every weak homotopy equivalence f:ABf:A\to B, the map f:[X,A][X,B]f_*:[X,A]\to [X,B] induced in homotopy classes is a bijection. For which spaces XX is f:[B,X][A,X]f^*:[B,X]\to [A,X] a bijection for every weak equivalence ff? This question was considered by J. Strom and T. Goodwillie. In this note we prove that a non-empty space inverts weak equivalences if and only if it is contractible.

Keywords

Cite

@article{arxiv.1709.08734,
  title  = {Spaces which invert weak homotopy equivalences},
  author = {Jonathan Ariel Barmak},
  journal= {arXiv preprint arXiv:1709.08734},
  year   = {2019}
}

Comments

3 pages

R2 v1 2026-06-22T21:54:31.817Z