English

Rosenthal families, pavings and generic cardinal invariants

Logic 2019-11-18 v2

Abstract

Following D. Sobota we call a family F\mathcal F of infinite subsets of N\mathbb N a Rosenthal family if it can replace the family of all infinite subsets of N\mathbb N in classical Rosenthal's Lemma concerning sequences of measures on pairwise disjoint sets. We resolve two problems on Rosenthal families: every ultrafilter is a Rosenthal family and the minimal size of a Rosenthal family is exactly equal to the reaping cardinal r\mathfrak r. This is achieved through analyzing nowhere reaping families of subsets of N\mathbb N and through applying a paving lemma which is a consequence of a paving lemma concerning linear operators on 1n\ell_1^n due to Bourgain. We use connections of the above results with free set results for functions on N\mathbb N and with linear operators on c0c_0 to determine the values of several other derived cardinal invariants.

Keywords

Cite

@article{arxiv.1911.01336,
  title  = {Rosenthal families, pavings and generic cardinal invariants},
  author = {Piotr Koszmider and Arturo Martínez-Celis},
  journal= {arXiv preprint arXiv:1911.01336},
  year   = {2019}
}

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