English

Non-meager free sets and independent families

General Topology 2017-06-21 v2 Logic

Abstract

Our main result is that, given a collection R\mathcal{R} of meager relations on a Polish space XX such that Rω|\mathcal{R}|\leq\omega, there exists a dense Baire subspace FF of XX (equivalently, a nowhere meager subset FF of XX) such that FF is RR-free for every RRR\in\mathcal{R}. This generalizes a recent result of Banakh and Zdomskyy. As an application, we show that there exists a non-meager independent family on ω\omega, and define the corresponding cardinal invariant. Furthermore, assuming Martin's Axiom for countable posets, our result can be strengthened by substituting "Rω|\mathcal{R}|\leq\omega" with "R<c|\mathcal{R}|<\mathfrak{c}" and "Baire" with "completely Baire".

Keywords

Cite

@article{arxiv.1508.00124,
  title  = {Non-meager free sets and independent families},
  author = {Andrea Medini and Dušan Repovš and Lyubomyr Zdomskyy},
  journal= {arXiv preprint arXiv:1508.00124},
  year   = {2017}
}

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13 pages