English

On (non-Menger) spaces whose closed nowhere dense subsets are Menger

General Topology 2025-01-24 v1

Abstract

A space XX is od-Menger if it satisfies Ufin(ΔX,OX)\mathsf{U_{fin}}(\Delta_X, \mathcal{O}_X), where OX,ΔX\mathcal{O}_X,\Delta_X are the collection of covers of XX by respectively open subsets and open dense subsets. We show that under CH, there is a refinement of the usual topology on a subset of the reals which yields a hereditarily Lindel\"of, od-Menger, non-Menger, 00-dimensional, first countable space. We also investigate the properties of spaces which are od-Menger but not Menger.

Keywords

Cite

@article{arxiv.2501.13220,
  title  = {On (non-Menger) spaces whose closed nowhere dense subsets are Menger},
  author = {Mathieu Baillif and Santi Spadaro},
  journal= {arXiv preprint arXiv:2501.13220},
  year   = {2025}
}
R2 v1 2026-06-28T21:14:09.373Z