English

Creature forcing and large continuum: The joy of halving

Logic 2012-01-04 v1

Abstract

For f,gωωf,g\in\omega^\omega let cf,gc^\forall_{f,g} be the minimal number of uniform gg-splitting trees needed to cover the uniform ff-splitting tree, i.e., for every branch ν\nu of the ff-tree, one of the gg-trees contains ν\nu. Let cf,gc^\exists_{f,g} be the dual notion: For every branch ν\nu, one of the gg-trees guesses ν(m)\nu(m) infinitely often. We show that it is consistent that cfϵ,gϵ=cfϵ,gϵ=κϵc^\exists_{f_\epsilon,g_\epsilon}=c^\forall_{f_\epsilon,g_\epsilon}=\kappa_\epsilon for continuum many pairwise different cardinals κϵ\kappa_\epsilon and suitable pairs (fϵ,gϵ)(f_\epsilon,g_\epsilon). For the proof we introduce a new mixed-limit creature forcing construction.

Keywords

Cite

@article{arxiv.1003.3425,
  title  = {Creature forcing and large continuum: The joy of halving},
  author = {Jakob Kellner and Saharon Shelah},
  journal= {arXiv preprint arXiv:1003.3425},
  year   = {2012}
}
R2 v1 2026-06-21T14:59:03.290Z