PFA AND THE DEFINABILITY OF THE NONSTATIONARY IDEAL
Abstract We produce, relative to a $\textsf {ZFC}$ model with a supercompact cardinal, a $\textsf {ZFC}$ model of the Proper Forcing Axiom in which the nonstationary ideal on $\omega _1$ is $\Pi _1$ -definable in a parameter from $H_{\aleph _2}$ .
Authors
- Paul Larson (ORCID: https://orcid.org/0000-0001-5931-7051)
- Stefan Hoffelner (ORCID: https://orcid.org/0000-0003-0434-6554)
- Liuzhen Wu (ORCID: https://orcid.org/0000-0002-5152-9268)
- Ralf Schindler (ORCID: https://orcid.org/0000-0001-5327-9138)
Institutions
- University of Münster (DE)
- Academy of Mathematics and Systems Science (CN)
- Miami University (US)
Publication Details
- Journal
- Journal of Symbolic Logic
- Published
- 2025-04-11
- DOI
- https://doi.org/10.1017/jsl.2025.31
- Primary Topic
- Computability, Logic, AI Algorithms
- Type
- article
- Field-Weighted Citation Impact
- 0.00