English

Ideal games and Ramsey sets

Combinatorics 2014-10-20 v3 Logic

Abstract

It is shown that Matet's characterization of the Ramsey property relative to a selective co-ideal H\mathcal{H}, in terms of games of Kastanas, still holds if we consider semiselectivity instead of selectivity. Moreover, we prove that a co-ideal H\mathcal{H} is semiselective if and only if Matet's game-theoretic characterization of the H\mathcal{H}-Ramsey property holds. This lifts Kastanas's characterization of the classical Ramsey property to its optimal setting, from the point of view of the local Ramsey theory and gives a game-theoretic counterpart to a theorem of Farah \cite{far}, asserting that a co-ideal H\mathcal{H} is semiselective if and only if the family of H\mathcal{H}-Ramsey subsets of N[]\N^{[\infty]} coincides with the family of those sets having the abstract H\mathcal{H}-Baire property. Finally, we show that under suitable assumptions, for every semiselective co-ideal H\mathcal H all sets of real numbers are H\mathcal H-Ramsey.

Cite

@article{arxiv.1009.3683,
  title  = {Ideal games and Ramsey sets},
  author = {Carlos Di Prisco and Jose G. Mijares and Carlos Uzcategui},
  journal= {arXiv preprint arXiv:1009.3683},
  year   = {2014}
}

Comments

11 pages

R2 v1 2026-06-21T16:15:56.898Z