English

On $\kappa$-Frechet-Urysohn topological groups

General Topology 2026-02-06 v2

Abstract

We characterize κ\kappa-Fr\'{e}chet--Urysohn topological groups. Using this characterization we show that: (1) a hemicompact topological group is κ\kappa-Fr\'{e}chet--Urysohn iff it is locally compact, and (2) if FF is a closed metrizable subspace of a topological vector space (tvs) EE such that the quotient E/FE/F is a κ\kappa-Fr\'{e}chet--Urysohn space, then also EE is a κ\kappa-Fr\'{e}chet--Urysohn space. Consequently, the product of a κ\kappa-Fr\'{e}chet--Urysohn tvs and a metrizable tvs is a κ\kappa-Fr\'{e}chet--Urysohn space. Under Martin's Axiom, we construct a countable Boolean κ\kappa-Fr\'{e}chet--Urysohn group which is not a kRk_{\mathbb R}-space.

Keywords

Cite

@article{arxiv.2602.04647,
  title  = {On $\kappa$-Frechet-Urysohn topological groups},
  author = {Saak Gabriyelyan and Alexander V. Osipov and Evgenii Reznichenko},
  journal= {arXiv preprint arXiv:2602.04647},
  year   = {2026}
}
R2 v1 2026-07-01T09:36:04.141Z