Published online by Cambridge University Press: 04 February 2019
We analyze the models $L[T_{2n} ]$, where
$T_{2n}$ is a tree on
$\omega \times \kappa _{2n + 1}^1 $ projecting to a universal
${\rm{\Pi }}_{2n}^1 $ set of reals, for
$n > 1$. Following Hjorth’s work on
$L[T_2 ]$, we show that under
${\rm{Det}}\left( {{\rm{}}_{2n}^1 } \right)$, the models
$L[T_{2n} ]$ are unique, that is they do not depend of the choice of the tree
$T_{2n}$. This requires a generalization of the Kechris–Martin theorem to all pointclasses
${\rm{\Pi }}_{2n + 1}^1$. We then characterize these models as constructible models relative to the direct limit of all countable nondropping iterates of
${\cal M}_{2n + 1}^\# $. We then show that the GCH holds in
$L[T_{2n} ]$, for every
$n < \omega $, even though they are not extender models. This analysis localizes the HOD analysis of Steel and Woodin at the even levels of the projective hierarchy.