Local Ramsey theory. An abstract approach

José Mijares; Jesús Nieto

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arXiv · 0712.2393

Local Ramsey theory. An abstract approach

José Mijares·Jesús Nieto

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Abstract

It is shown that the known notion of selective coideal can be extended to a family $\mathcal{H}$ of subsets of $\mathcal{R}$, where $(\mathcal{R},\leq,r)$ is a topological Ramsey space in the sense of Todorcevic (see \cite{todo}). Then it is proven that, if $\mathcal{H}$ selective, the $\mathcal{H}$-Ramsey and $\mathcal{H}$-Baire subsets of $\mathcal{R}$ are equivalent. This extends the results of Farah in \cite{farah} for semiselective coideals of $\mathbb{N}$. Also, it is proven that the family of ${\cal H}$--Ramsey subsets of ${\cal R}$ is closed under the Souslin operation.

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BibTeX RIS

José Mijares, Jesús Nieto. 2007-12-14. Local Ramsey theory. An abstract approach. https://arxiv.org/abs/0712.2393

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