Determinacy from strong compactness of $\omega_1$
Logic
2016-09-20 v1
Abstract
In the absence of the Axiom of Choice, the "small" cardinal can exhibit properties more usually associated with large cardinals, such as strong compactness and supercompactness. For a local version of strong compactness, we say that is -strongly compact (where is any set) if there is a fine, countably complete measure on . Working in , we prove that the -strong compactness and -strong compactness of are equiconsistent with and respectively, where denotes the Axiom of Determinacy and denotes the Axiom of Real Determinacy. The -supercompactness of is shown to be slightly stronger than , but its consistency strength is not computed precisely. An equiconsistency result at the level of without is also obtained.
Cite
@article{arxiv.1609.05411,
title = {Determinacy from strong compactness of $\omega_1$},
author = {Nam Trang and Trevor Wilson},
journal= {arXiv preprint arXiv:1609.05411},
year = {2016}
}