English

Incompatible bounded category forcing axioms

Logic 2021-01-11 v1

Abstract

We introduce bounded category forcing axioms for well-behaved classes Γ\Gamma. These are strong forms of bounded forcing axioms which completely decide the theory of some initial segment of the universe HλΓ+H_{\lambda_\Gamma^+} modulo forcing in Γ\Gamma, for some cardinal λΓ\lambda_\Gamma naturally associated to Γ\Gamma. These axioms naturally extend projective absoluteness for arbitrary set-forcing--in this situation λΓ=ω\lambda_\Gamma=\omega--to classes Γ\Gamma with λΓ>ω\lambda_\Gamma>\omega. Unlike projective absoluteness, these higher bounded category forcing axioms do not follow from large cardinal axioms, but can be forced under mild large cardinal assumptions on VV. We also show the existence of many classes Γ\Gamma with λΓ=ω1\lambda_\Gamma=\omega_1, and giving rise to pairwise incompatible theories for Hω2H_{\omega_2}.

Keywords

Cite

@article{arxiv.2101.03132,
  title  = {Incompatible bounded category forcing axioms},
  author = {David Aspero and Matteo Viale},
  journal= {arXiv preprint arXiv:2101.03132},
  year   = {2021}
}

Comments

arXiv admin note: substantial text overlap with arXiv:1805.08732

R2 v1 2026-06-23T21:55:37.063Z