English

Every metric space of weight $\lambda=\lambda^{\aleph_0}$ admits a condensation onto a Banach space

General Topology 2022-02-10 v1

Abstract

In this paper, we have proved that for each cardinal number λ\lambda such that λ=λ0\lambda=\lambda^{\aleph_0} a metric space of weight λ\lambda admits a bijective continuous mapping onto a Banach space of weight λ\lambda. Then, we get that every metric space of weight continuum admits a bijective continuous mapping onto the Hilbert cube. This resolves the famous Banach's Problem (when does a metric (possibly Banach) space XX admit a bijective continuous mapping onto a compact metric space?) in the class of metric spaces of weight continuum. Also we get that every metric space of weight λ=λ0\lambda=\lambda^{\aleph_0} admits a bijective continuous mapping onto a Hausdorff compact space. This resolves the Alexandroff Problem (when does a Hausdorff space XX admit a bijective continuous mapping onto a Hausdorff compact space?) in the class of metric spaces of weight λ=λ0\lambda=\lambda^{\aleph_0}.

Keywords

Cite

@article{arxiv.2202.04576,
  title  = {Every metric space of weight $\lambda=\lambda^{\aleph_0}$ admits a condensation onto a Banach space},
  author = {Alexander V. Osipov and Evgenii G. Pytkeev},
  journal= {arXiv preprint arXiv:2202.04576},
  year   = {2022}
}

Comments

8 pages

R2 v1 2026-06-24T09:28:38.759Z