English

Higher Dimensional Cardinal Characteristics for Sets of Functions

Logic 2021-09-01 v2

Abstract

Much recent work in cardinal characteristics has focused on generalizing results about ω\omega to uncountable cardinals by studying analogues of classical cardinal characteristics on the generalized Baire and Cantor spaces κκ\kappa^\kappa and 2κ2^\kappa. In this note I look at generalizations to other function spaces, focusing particularly on the space of functions f:ωωωωf:\omega^\omega \to \omega^\omega. By considering classical cardinal invariants on Baire space in this setting I derive a number of "higher dimensional" analogues of such cardinals, ultimately introducing 18 new cardinal invariants, alongside a framework that allows for numerous others. These 18 form two separate diagrams consisting of 6 and 12 cardinals respectively, each resembling versions of the Cicho\'n diagram. These ZFC-inequalities are the first main result of the paper. I then consider other relations between these cardinals, as well as the cardinal c+\mathfrak{c}^+ and show that these results rely on additional assumptions about cardinal characteristics on ω\omega. Finally, using variations of Cohen, Hechler, and localization forcing I prove a number of consistency results for possible values of the new cardinals.

Keywords

Cite

@article{arxiv.1909.07458,
  title  = {Higher Dimensional Cardinal Characteristics for Sets of Functions},
  author = {Corey Bacal Switzer},
  journal= {arXiv preprint arXiv:1909.07458},
  year   = {2021}
}

Comments

20 pages, 3 figures, updated version fixes some minor errors and reflects the status of the general research project as many previously open questions have now been answered by the author and Brendle in another paper. Now accepted at the Annals of Pure and Applied Logic

R2 v1 2026-06-23T11:17:13.670Z