English

Proper actions on topological groups: Applications to quotient spaces

General Topology 2012-09-04 v2 Geometric Topology

Abstract

Let X be a Hausdorff topological group and G a locally compact subgroup of X. We show that the natural action of G on X is proper in the sense of R. Palais. This is applied to prove that there exists a closed set F of X such that FG=X and the restriction of the quotient projection X -> X/G to F is a perfect map F -> X/G. This is a key result to prove that many topological properties (among them, paracompactness and normality) are transferred from X to ferred from X/G to X. Yet another application leads to the inequality dim X<= dim X/G + dim G for every paracompact group X and its locally compact subgroup G.

Keywords

Cite

@article{arxiv.0905.2616,
  title  = {Proper actions on topological groups: Applications to quotient spaces},
  author = {Sergey A. Antonyan},
  journal= {arXiv preprint arXiv:0905.2616},
  year   = {2012}
}

Comments

In the proof of Proposition 3.1 of the previous version there is a small gap. To correct the gap, at the end of the proof (now Proposition 3.2) one should just reference to a newly added Lemma 3.1 for the fact that Ux is a G-small set. Results unchanged. arXiv admin note: substantial text overlap with arXiv:1103.1407

R2 v1 2026-06-21T13:02:50.710Z