Pure subrings of regular rings are pseudo-rational

Abstract

We prove a generalization conjectured by Aschenbrenner and Schoutens (2003) of the Hochster-Roberts-Boutot-Kawamata Theorem: let R → S R\to S be a pure homomorphism of equicharacteristic zero Noetherian local rings. If S S is regular, then R R is pseudo-rational, and if R R is moreover Q \mathbb Q -Gorenstein, then it is pseudo-log-terminal.