English

Blowing up the power of a singular cardinal of uncountable cofinality with collapses

Logic 2022-02-23 v3

Abstract

The {\em Singular Cardinal Hypothesis} (SCH) is one of the most classical combinatorial principles in set theory. It says that if κ\kappa is singular strong limit, then 2κ=κ+2^{\kappa}=\kappa^+. We prove that given a singular cardinal κ\kappa of {\em cofinality} η\eta in the ground model, which is a limit of suitable large cardinals, and η+=γ\eta^+=\aleph_{\gamma}, then there is a forcing extension which preserves cardinals and cofinalities up to and including η\eta, such that κ\kappa becomes γ+η\aleph_{\gamma+\eta}, and SCH fails at κ\kappa. Furthermore, if η\eta is not an \aleph-fixed point, then in our model, SCH fails at η\aleph_{\eta}. Our large cardinal assumption is below the existence of a Woodin cardinal. In our model we also obtain a very good scale.

Keywords

Cite

@article{arxiv.2011.00409,
  title  = {Blowing up the power of a singular cardinal of uncountable cofinality with collapses},
  author = {Sittinon Jirattikansakul},
  journal= {arXiv preprint arXiv:2011.00409},
  year   = {2022}
}

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28 pages