Nonregular ideals
Logic
2020-09-04 v2
Abstract
Generalizing Keisler's notion of regularity for ultrafilters, Taylor introduced degrees of regularity for ideals and showed that a countably complete nonregular ideal on must be somewhere -dense. We prove a dichotomy about degrees of regularity for -complete ideals on successor cardinals and apply this to show that Taylor's Theorem does not generalize to higher cardinals. In particular, the existence of a nonregular ideal on does not imply the existence of an -dense ideal on . We obtain similar results for normal ideals on .
Keywords
Cite
@article{arxiv.1901.02822,
title = {Nonregular ideals},
author = {Monroe Eskew},
journal= {arXiv preprint arXiv:1901.02822},
year = {2020}
}