Singularity categories of deformations of Kleinian singularities

Abstract

Let $G$ be a finite subgroup of $\text{SL}(2,\mathbb{k})$ and let $R=\mathbb{k}[x,y{]}^G$ be the coordinate ring of the corresponding Kleinian singularity. In 1998, Crawley-Boevey and Holland defined deformations ${\mathcal{O}}^{\lambda }$ of $R$ parametrised by weights $\lambda$. In this paper, we determine the singularity categories ${\mathcal{D}}_{\text{sg}}({\mathcal{O}}^{\lambda })$ of these deformations, and show that they correspond to subgraphs of the Dynkin graph associated to $R$. This generalises known results on the structure of ${\mathcal{D}}_{\text{sg}}(R)$. We also provide a generalisation of the intersection theory appearing in the geometric McKay correspondence to a noncommutative setting.

Substantial revision to the previous version, which uses a shorter argument to prove the main theorem. To appear in Algebra & Number Theory

References in corpus (2)

• Relative singularity categories II: DG models
• Singularity categories of deformations of Kleinian singularities

Cited by in corpus (4)

• Relative singularity categories II: DG models
• Auslander-Reiten duality for subcategories
• Singularity categories of deformations of Kleinian singularities
• A remark on a theorem by C. Amiot