Logic Seminar
Paul LarsonMiami University
Failures of square in $\pmax$ extensions of Chang models, and the iterability problem for $K^c$
Friday, November 17, 2023 - 2:55pm
Malott 205
The Chang model is the smallest model of ZF containing every countable set of ordinals. Forcing over a variant of the Chang model of determinacy, we obtain a model of ZFC satisfying the theory in which Jensen's square principle fails at $\omega_{3}$ and $\omega_{4}$. In this model, the Iterability Conjecture fails for the Mitchell-Schindler version of $\sf{K}^c$. This is joint work with Grigor Sargsyan.