English

The Horizontal Direction

Logic 2025-03-07 v1

Abstract

We give a survey of cardinal charcteristics of the higher Cicho\'n diagram defined on the higher Baire space κκ{}^\kappa\kappa for κ\kappa regular with 2<κ=κ2^{<\kappa}=\kappa. Specifically, we will compare consistency proofs from the classical Cicho\'n diagram with various well-known forcing notions to similar constructions generalised to the higher Cicho\'n diagram. We are especially interested in separation in a horizontal direction, that is, the consistency of add(Mκ)<non(Mκ)\mathrm{add}(\mathcal M_\kappa)<\mathrm{non}(\mathcal M_\kappa) and of cov(Mκ)<cof(Mκ)\mathrm{cov}(\mathcal M_\kappa)<\mathrm{cof}(\mathcal M_\kappa). We will have a look at (higher analogues of) Cohen, Hechler, localisation, eventually different, Sacks, random, Laver, Mathias and Miller forcing, and their effect on the cardinal characteristics of the higher Cicho\'n diagram.

Keywords

Cite

@article{arxiv.2503.04471,
  title  = {The Horizontal Direction},
  author = {Tristan van der Vlugt},
  journal= {arXiv preprint arXiv:2503.04471},
  year   = {2025}
}

Comments

30 pages, survey article, submitted to RIMS kokyuroku

R2 v1 2026-06-28T22:09:16.318Z