English

Iterating Generalised Perfect Set Forcing Along Well-Founded Orders

Logic 2026-04-14 v1

Abstract

Vladimir Kanovei \cite{zbMATH01335192} developed the technique of geometric iteration and used it to prove that the perfect set forcing can be iterated with countable supports along any partial order, while preserving 1\aleph_1. In \cite{Property-B} we considered a generalised perfect set forcing with respect to a filter on a cardinal κ\kappa satisfying κ<κ=κ\kappa^{<\kappa}=\kappa, which we denoted P(F){\mathbb P} (\mathcal F), and proved that its iteration with supports of size κ\le\kappa along any ordinal preserves cardinals up and including κ+\kappa^+. We show that there is a version of the geometric iteration technique that applies to P(F){\mathbb P} (\mathcal F), to yield that for κ\kappa satisfying κ<κ=κ\kappa^{<\kappa}=\kappa, the forcing P(\FF){\mathbb P} (\FF) can be iterated with supports of size κ\le\kappa along any well-founded partial order, while preserving cardinals up and including κ+\kappa^+.

Keywords

Cite

@article{arxiv.2604.10826,
  title  = {Iterating Generalised Perfect Set Forcing Along Well-Founded Orders},
  author = {Mirna Džamonja},
  journal= {arXiv preprint arXiv:2604.10826},
  year   = {2026}
}

Comments

A preprint in view of the submission to a special issue of the Proceedings of the Steklov Institute

R2 v1 2026-07-01T12:05:19.702Z