Ramsey Property and Pathological Sets: Almost Disjointness, Independence and Other Maximal Objects

Fuente: arXiv
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Autori principali: He, Jialiang, Luo, Jintao, Zhang, Shuguo
Natura: Preprint
Pubblicazione: 2026
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author He, Jialiang
Luo, Jintao
Zhang, Shuguo
author_facet He, Jialiang
Luo, Jintao
Zhang, Shuguo
contents We show that under $\mathsf{ZF} + \mathsf{CC}_{\mathbb R}$, if the Ramsey property holds for all sets in a good pointclass $Γ$, then there is no MAD family in $Γ$, proving a long-standing conjecture made by A.R.D.\ Mathias in 1977. This also holds for $\mathcal I$-MAD families with respect to analytic ideals $\mathcal I$ including $\mathcal{ED}$, $\mathcal{ED}_{\mathrm{fin}}$, and $\finalphaα$ for all countable ordinals $α$. Under the same assumption, we show that if any one of the Baire property, Lebesgue measurability or Ramsey property holds for all sets in $Γ$, then there is no maximal independent family in $Γ$. Under the stronger assumption $\mathsf{ZF} + \mathsf{DC}_{\mathbb R}$, we further prove that if the Ramsey property holds for all sets in $Γ$, then $Γ$ contains no Vitali sets and thus no Hamel bases.
format Preprint
id arxiv_https___arxiv_org_abs_2604_26570
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Ramsey Property and Pathological Sets: Almost Disjointness, Independence and Other Maximal Objects
He, Jialiang
Luo, Jintao
Zhang, Shuguo
Logic
We show that under $\mathsf{ZF} + \mathsf{CC}_{\mathbb R}$, if the Ramsey property holds for all sets in a good pointclass $Γ$, then there is no MAD family in $Γ$, proving a long-standing conjecture made by A.R.D.\ Mathias in 1977. This also holds for $\mathcal I$-MAD families with respect to analytic ideals $\mathcal I$ including $\mathcal{ED}$, $\mathcal{ED}_{\mathrm{fin}}$, and $\finalphaα$ for all countable ordinals $α$. Under the same assumption, we show that if any one of the Baire property, Lebesgue measurability or Ramsey property holds for all sets in $Γ$, then there is no maximal independent family in $Γ$. Under the stronger assumption $\mathsf{ZF} + \mathsf{DC}_{\mathbb R}$, we further prove that if the Ramsey property holds for all sets in $Γ$, then $Γ$ contains no Vitali sets and thus no Hamel bases.
title Ramsey Property and Pathological Sets: Almost Disjointness, Independence and Other Maximal Objects
topic Logic
url https://arxiv.org/abs/2604.26570