Second-countable compact Hausdorff spaces as remainders in $\mathbf{ZF}$ and two new notions of infiniteness
Abstract
In the absence of the Axiom of Choice, necessary and sufficient conditions for a locally compact Hausdorff space to have all non-empty second-countable compact Hausdorff spaces as remainders are given in . Among other independence results, the characterization of locally compact Hausdorff spaces having all non-empty metrizable compact spaces as remainders, obtained by Hatzenhuhler and Mattson in , is proved to be independent of . Urysohn's Metrization Theorem is generalized to the following theorem: every -space which admits a base expressible as a countable union of finite sets is metrizable. Applications to solutions of problems concerning the existence of some special metrizable compactifications in are shown. New concepts of a strongly filterbase infinite set and a dyadically filterbase infinite set are introduced, both stemming from the investigations on compactifications. Set-theoretic and topological definitions of the new concepts are given, and their relationship with certain known notions of infinite sets is investigated in . A new permutation model is introduced in which there exists a strongly filterbase infinite set which is weakly Dedekind-finite. All -independence results of this article are transferable to .
Keywords
Cite
@article{arxiv.2009.09526,
title = {Second-countable compact Hausdorff spaces as remainders in $\mathbf{ZF}$ and two new notions of infiniteness},
author = {Kyriakos Keremedis and Eleftherios Tachtsis and Eliza Wajch},
journal= {arXiv preprint arXiv:2009.09526},
year = {2020}
}