English

Condensable models of set theory

Logic 2021-06-21 v4

Abstract

We study models M of set theory that are "condensable", in the sense that there is an "ordinal" v of M such that the rank initial segment of M determined by v is both isomorphic to M, and also an elementary submodel of M for infinitary formulae in the well-founded part of M. We prove, assuming a modest set theoretic hypothesis, that there are condensable models M of ZFC such that every definable element of M is in the well-founded part of M. We also provide various characterizations of countable condensable models of ZF.

Keywords

Cite

@article{arxiv.1910.04029,
  title  = {Condensable models of set theory},
  author = {Ali Enayat},
  journal= {arXiv preprint arXiv:1910.04029},
  year   = {2021}
}

Comments

15 pages (this is revised version of a previously posted draft)

R2 v1 2026-06-23T11:38:46.007Z