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arXiv · 1910.14483

On first countable, cellular-compact spaces

Abstract

As it was introduced by Tkachuk and Wilson, a topological space $X$ is cellular-compact if given any cellular, i.e. disjoint, family $\mathcal U$ of non-empty open subsets of $X$ there is a compact subspace $K\subset X$ such that $K\cap U\ne \emptyset$ for each $U\in \mathcal U$. Answering several questions raised by Tkachuk and Wilson we show that (1) any first countable cellular-compact $T_2$ space is $T_3$, and so its cardinality is at most $\mathfrak{c} = 2^ω$; (2) $cov(\mathcal M)>ω_1$ implies that every first countable and separable cellular-compact $T_2$ space is compact; (3 if there is no $S$-space then any cellular-compact $T_3$ space of countable spread is compact; (4) $MA_{ω_1}$ implies that every point of a compact $T_2$ space of countable spread has a disjoint local $π$-base.

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BibTeXRIS

István Juhász, Lajos Soukup, Zoltán Szentmiklóssy. 2019-12-18. On first countable, cellular-compact spaces. https://arxiv.org/abs/1910.14483

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