A McKay correspondence for reflection groups
Abstract
We construct a noncommutative desingularization of the discriminant of a finite reflection group as a quotient of the skew group ring . If is generated by order two reflections, then this quotient identifies with the endomorphism ring of the reflection arrangement viewed as a module over the coordinate ring of the discriminant of . This yields, in particular, a correspondence between the nontrivial irreducible representations of to certain maximal Cohen--Macaulay modules over the coordinate ring . These maximal Cohen--Macaulay modules are precisely the nonisomorphic direct summands of the coordinate ring of the reflection arrangement viewed as a module over . We identify some of the corresponding matrix factorizations, namely the so-called logarithmic (co-)residues of the discriminant.
Cite
@article{arxiv.1709.04218,
title = {A McKay correspondence for reflection groups},
author = {Ragnar-Olaf Buchweitz and Eleonore Faber and Colin Ingalls},
journal= {arXiv preprint arXiv:1709.04218},
year = {2020}
}
Comments
Major revision. Final version, to appear in Duke Math. Journal. 52pages