Generalized cardinal invariants for an inaccessible $\kappa$ with compactness at $\kappa^{++}$
Abstract
We show that if the existence of a supercompact cardinal with a weakly compact cardinal above is consistent, then the following are consistent as well (where and are the tower number and the ultrafilter number, respectively): (i) There is an inaccessible cardinal such that and hold, and (ii) There is an inaccessible cardinal such that and and hold. The cardinals and can have any reasonable values in these models. We obtain these results by combining the forcing construction from Brooke-Taylor, Fischer, Friedman and Montoya with the Mitchell forcing and with (new and old) indestructibility results for compactness principles. Apart from and we also compute the values of , , , , , , , , which will all be equal to . In (ii), we compute by observing that the -distributive quotient of the Mitchell forcing adds a tower of size . Finally, we observe that (i) and (ii) hold also for the traditional invariants on , using Mitchell forcing up to a weakly compact cardinal; in this case we also obtain the disjoint stationary sequence property , which implies the negation of the approachability property .
Keywords
Cite
@article{arxiv.2308.13478,
title = {Generalized cardinal invariants for an inaccessible $\kappa$ with compactness at $\kappa^{++}$},
author = {Radek Honzik and Sarka Stejskalova},
journal= {arXiv preprint arXiv:2308.13478},
year = {2025}
}
Comments
27 pages, to appear in Archive for Mathematical Logic. A substantial revision of the previous version with more details (also regarding the principle DSS)