English

Several amazing discoveries about compact metrizable spaces in ZF

General Topology 2020-08-05 v1

Abstract

In the absence of the axiom of choice, the set-theoretic status of many natural statements about metrizable compact spaces is investigated. Some of the statements are provable in ZF\mathbf{ZF}, some are shown to be independent of ZF\mathbf{ZF}. For independence results, distinct models of ZF\mathbf{ZF} and permutation models of ZFA\mathbf{ZFA} with transfer theorems of Pincus are applied. New symmetric models are constructed in each of which the power set of R\mathbb{R} is well-orderable, the Continuum Hypothesis is satisfied but a denumerable family of non-empty finite sets can fail to have a choice function, and a compact metrizable space need not be embeddable into the Tychonoff cube [0,1]R[0, 1]^{\mathbb{R}}.

Keywords

Cite

@article{arxiv.2008.01233,
  title  = {Several amazing discoveries about compact metrizable spaces in ZF},
  author = {Kyriakos Keremedis and Eleftherios Tachtsis and Eliza Wajch},
  journal= {arXiv preprint arXiv:2008.01233},
  year   = {2020}
}