Distinguishing Internally Club and Approachable on an Infinite Interval
Logic
2024-04-24 v1
Abstract
Krueger showed that PFA implies that for all regular , there are stationarily many that are internally club but not internally approachable. From countably many Mahlo cardinals, we force a model in which, for all positive and , there is a stationary subset of consisting of sets that are internally club but not internally approachable. The theorem is obtained using a new variant of Mitchell forcing. This answers questions of Krueger.
Keywords
Cite
@article{arxiv.2404.15230,
title = {Distinguishing Internally Club and Approachable on an Infinite Interval},
author = {Hannes Jakob and Maxwell Levine},
journal= {arXiv preprint arXiv:2404.15230},
year = {2024}
}