On Namba Forcing And Minimal Collapses
Abstract We build on a 1990 paper of Bukovský and Copláková-Hartová. First, we remove the hypothesis of ${\mathsf {CH}}$ from one of their minimality results. Then, using a measurable cardinal, we show that there is a $|\aleph _2^V|=\aleph _1$ -minimal extension that is not a $|\aleph _3^V|=\aleph _1$ -extension, answering the first of their questions.
Authors
- Maxwell Levine (ORCID: https://orcid.org/0000-0001-7150-102X)
Institutions
- University of Freiburg (DE)
Publication Details
- Journal
- Forum of Mathematics Sigma
- Published
- 2025-01-01
- DOI
- https://doi.org/10.1017/fms.2025.10106
- Primary Topic
- Advanced Topology and Set Theory
- Type
- article
- Field-Weighted Citation Impact
- 0.00