Singularity categories of rational double points in arbitrary characteristic

Fuente: arXiv
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Main Authors: Takashima, Yuta, Uehara, Hokuto
Format: Preprint
Published: 2024
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_version_ 1866912053919219712
author Takashima, Yuta
Uehara, Hokuto
author_facet Takashima, Yuta
Uehara, Hokuto
contents We establish a one-to-one correspondence between the singularity categories of rational double points and the simply-laced Dynkin graphs in arbitrary characteristic. This correspondence is well-known in characteristic zero since the rational double points are quotient singularities in characteristic zero whereas not necessarily in positive characteristic. Considering some rational double points are not taut in characteristic two, three or five, we can see there exist two rational double points which are not analytically isomorphic but whose singularity categories are triangulated equivalent. As an application, we construct a counter-example in positive characteristic of a theorem of Hua and Keller: the dg singularity category of a hypersurface singularity determines its Tyurina algebra.
format Preprint
id arxiv_https___arxiv_org_abs_2408_02532
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Singularity categories of rational double points in arbitrary characteristic
Takashima, Yuta
Uehara, Hokuto
Algebraic Geometry
Category Theory
Representation Theory
14F08 (Primary) 14B05, 16G50, 16G70, 18G80 (Secondary)
We establish a one-to-one correspondence between the singularity categories of rational double points and the simply-laced Dynkin graphs in arbitrary characteristic. This correspondence is well-known in characteristic zero since the rational double points are quotient singularities in characteristic zero whereas not necessarily in positive characteristic. Considering some rational double points are not taut in characteristic two, three or five, we can see there exist two rational double points which are not analytically isomorphic but whose singularity categories are triangulated equivalent. As an application, we construct a counter-example in positive characteristic of a theorem of Hua and Keller: the dg singularity category of a hypersurface singularity determines its Tyurina algebra.
title Singularity categories of rational double points in arbitrary characteristic
topic Algebraic Geometry
Category Theory
Representation Theory
14F08 (Primary) 14B05, 16G50, 16G70, 18G80 (Secondary)
url https://arxiv.org/abs/2408.02532