Article contents
Approachability at the second successor of a singular cardinal
Published online by Cambridge University Press: 12 March 2014
Abstract
We prove that if μ is a regular cardinal and ℙ is a μ-centered forcing poset, then ℙ forces that (I[μ++[)V generates I[μ++] modulo clubs. Using this result, we construct models in which the approachability property fails at the successor of a singular cardinal. We also construct models in which the properties of being internally club and internally approachable are distinct for sets of size the successor of a singular cardinal.
- Type
- Research Article
- Information
- Copyright
- Copyright © Association for Symbolic Logic 2009
References
REFERENCES
- 5
- Cited by