Forcing the $Π^1_n$-Uniformization Property

Stefan Hoffelner

Published 2021-03-22Version 1

We generically construct a model in which the ${\Pi^1_3}$-uniformization property is true, thus lowering the best known consistency strength from the existence of $M_1^{\#}$ to just $\mathsf{ZFC}$. The forcing construction can be adapted to work over canonical inner models with Woodin cardinals, which yields, for the first time, universes where the $\Pi^1_{2n}$-uniformization property holds, thus producing models which contradict the natural $\mathsf{PD}$-induced pattern. It can also be used to obtain models for the $\Pi^1_1$-uniformization property in the generalized Baire space.