Comparing the Kirwan and noncommutative resolutions of quotient varieties
Algebraic Geometry
2026-02-18 v2 Rings and Algebras
Representation Theory
Abstract
Let a reductive group act on a smooth variety such that a good quotient exists. We show that the derived category of a noncommutative crepant resolution (NCCR) of , obtained from a -equivariant vector bundle on , can be embedded in the derived category of the (canonical, stacky) Kirwan resolution of . In fact the embedding can be completed to a semi-orthogonal decomposition in which the other parts are all derived categories of Azumaya algebras over smooth Deligne-Mumford stacks.
Keywords
Cite
@article{arxiv.1912.01689,
title = {Comparing the Kirwan and noncommutative resolutions of quotient varieties},
author = {Špela Špenko and Michel Van den Bergh},
journal= {arXiv preprint arXiv:1912.01689},
year = {2026}
}
Comments
40 pages. v2: Correct ERC funding acknowledgement