English

On supercompactness and the continuum function

Logic 2013-09-12 v3

Abstract

Given a cardinal κ\kappa that is λ\lambda-supercompact for some regular cardinal λκ\lambda\geq\kappa and assuming \GCH\GCH, we show that one can force the continuum function to agree with any function F:[κ,λ]\REG\CARDF:[\kappa,\lambda]\cap\REG\to\CARD satisfying α,β\dom(F)\forall\alpha,\beta\in\dom(F) α<\cf(F(α))\alpha<\cf(F(\alpha)) and α<β\alpha<\beta     \implies F(α)F(β)F(\alpha)\leq F(\beta), while preserving the λ\lambda-supercompactness of κ\kappa from a hypothesis that is of the weakest possible consistency strength, namely, from the hypothesis that there is an elementary embedding j:VMj:V\to M with critical point κ\kappa such that MλMM^\lambda\subseteq M and j(κ)>F(λ)j(\kappa)>F(\lambda). Our argument extends Woodin's technique of surgically modifying a generic filter to a new case: Woodin's key lemma applies when modifications are done on the range of jj, whereas our argument uses a new key lemma to handle modifications done off of the range of jj on the ghost coordinates. This work answers a question of Friedman and Honzik [FH2012]. We also discuss several related open questions.

Keywords

Cite

@article{arxiv.1306.0449,
  title  = {On supercompactness and the continuum function},
  author = {Brent Cody and Menachem Magidor},
  journal= {arXiv preprint arXiv:1306.0449},
  year   = {2013}
}

Comments

12 pages

R2 v1 2026-06-22T00:27:05.610Z