Crepant resolutions of log-terminal singularities via Artin stacks

Abstract

We prove that every variety with log-terminal singularities admits a crepant resolution by a smooth Artin stack. We additionally prove new McKay correspondences for resolutions by Artin stacks, expressing stringy invariants of $\mathbb{Q}$-Gorenstein varieties in terms of motivic integrals on arc spaces of smooth stacks. In the crepant case, these McKay correspondences are particularly simple, demonstrating one example of the utility of crepant resolutions by Artin stacks.