English

The Bristol Model: an abyss called a Cohen real

Logic 2018-11-30 v4

Abstract

We construct a model MM of ZF which lies between LL and L[c]L[c] for a Cohen real cc and does not have the form L(x)L(x) for any set xx. This is loosely based on the unwritten work done in a Bristol workshop about Woodin's HOD Conjecture in 2011. The construction given here allows for a finer analysis of the needed assumptions on the ground models, thus taking us one step closer to understanding models of ZF, and the HOD Conjecture and its relatives. This model also provides a positive answer to a question of Grigorieff about intermediate models of ZF, and we use it to show the failure of Kinna--Wagner Principles in ZF.

Keywords

Cite

@article{arxiv.1704.06939,
  title  = {The Bristol Model: an abyss called a Cohen real},
  author = {Asaf Karagila},
  journal= {arXiv preprint arXiv:1704.06939},
  year   = {2018}
}

Comments

31 pages; post-refereeing version; minor corrections