English

Shelah Ultrafilters

Logic 2025-12-10 v1

Abstract

In this paper, we study a special type of ultrafilter which we call Shelah ultrafilter. We show that it is possible to add a Shelah ultrafilter using a special forcing notion. We also show that Shelah ultrafilters turn out to be I-ultrafilters for many Borel ideals.

Keywords

Cite

@article{arxiv.2512.08081,
  title  = {Shelah Ultrafilters},
  author = {Emmanuel Balderas and David Chodounský and Osvaldo Guzmán},
  journal= {arXiv preprint arXiv:2512.08081},
  year   = {2025}
}

Comments

21 pages

R2 v1 2026-07-01T08:15:48.947Z