English

Adding highly undefinable sets over $L$

Logic 2023-11-07 v1

Abstract

We sow that there exists a generic extension of the G\"{o}del's constructible universe in which diamond holds and there exists a subset Yω1Y \subseteq \omega_1 such that for stationary many δ<ω1,\delta < \omega_1, the set YδY \cap \delta is not definable in the structure (LF(δ),)(L_{F(\delta)}, \in), where F(δ)>δF(\delta) > \delta is the least ordinal such that LF(δ)L_{F(\delta)}\models``δ\delta is countable''.

Keywords

Cite

@article{arxiv.2311.02322,
  title  = {Adding highly undefinable sets over $L$},
  author = {Mohammad Golshani and Saharon Shelah},
  journal= {arXiv preprint arXiv:2311.02322},
  year   = {2023}
}

Comments

This is publication number 1227 in Shelah's list

R2 v1 2026-06-28T13:11:26.166Z