Galvin's property at large cardinals and the axiom of determinancy

Tom Benhamou, Shimon Garti, Alejandro Poveda

Published 2022-07-15Version 1

In the first part of this paper, we explore the possibility for a very large cardinal $\kappa$ to carry a $\kappa$-complete ultrafilter without Galvin's property. In this context, we prove the consistency of every ground model $\kappa$-complete ultrafilter extends to a non-Galvin one. Oppositely, it is also consistent that every ground model $\kappa$-complete ultrafilter extends to a $P$-point ultrafilter, hence to another one satisfying Galvin's property. We also study Galvin's property at large cardinals in the choiceless context, especially under \textsf{AD}. Finally, we apply this property to a classical pro\-blem in partition calculus by proving the relation $\lambda\rightarrow(\lambda,\omega+1)^2$ under ``\textsf{AD}+$V=L(\mathbb{R})$'' for unboundedly many $\lambda>{\rm cf}(\lambda)>\omega$ below $\Theta$.