Special Cohen--Macaulay sheaves on partial resolutions of rational surfaces singularities
Abstract
We introduce the categories CM(X) and SCM(X) of reflexive sheaves on a minimal partial resolution f: X → Spec R of a rational surface singularity Spec R. The main result of this paper establishes that SCM(X) possesses a natural Frobenius structure, serving as a geometric counterpart to the algebraic Frobenius structure on special Cohen--Macaulay R-modules, introduced by Iyama--Wemyss and Iyama--Kalck--Wemyss--Yang. Utilizing this geometric framework, we establish an exact equivalence between SCM(X) and the category of special Cohen--Macaulay R-modules equipped with a specific exact structure, which induces a triangle equivalence between their stable categories. Consequently, this provides a direct, geometric proof of the Iyama--Kalck--Wemyss--Yang equivalence and yields a Buchweitz-type equivalence underlineSCM(X) ≃ Dsg(X).
Related
- Crepant resolutions of fiber products and Kummer fibrations of rational elliptic surfaces with non-reduced fibers
- Isolated symplectic singularities admitting symplectic resolutions
- Resolutions of linear p-cyclic quotient singularities
- Noncommutative resolutions of noncommutative isolated singularities
- The embedded Nash problem of birational models of rational triple singularities
BibTeX
@misc{uehara2026special,
title = {{Special Cohen--Macaulay sheaves on partial resolutions of rational surfaces singularities}},
author = {Hokuto Uehara},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.30645},
eprint = {2609.30645},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.30645},
}
RIS
TY - UNPB
TI - Special Cohen--Macaulay sheaves on partial resolutions of rational surfaces singularities
AU - Hokuto Uehara
PY - 2026
DA - 2026/09/25
PB - arXiv
DO - 10.48550/arxiv.2609.30645
UR - https://arxiv.org/abs/2609.30645
AB - We introduce the categories CM(X) and SCM(X) of reflexive sheaves on a minimal partial resolution f: X → Spec R of a rational surface singularity Spec R. The main result of this paper establishes that SCM(X) possesses a natural Frobenius structure, serving as a geometric counterpart to the algebraic Frobenius structure on special Cohen--Macaulay R-modules, introduced by Iyama--Wemyss and Iyama--Kalck--Wemyss--Yang. Utilizing this geometric framework, we establish an exact equivalence between SCM(X) and the category of special Cohen--Macaulay R-modules equipped with a specific exact structure, which induces a triangle equivalence between their stable categories. Consequently, this provides a direct, geometric proof of the Iyama--Kalck--Wemyss--Yang equivalence and yields a Buchweitz-type equivalence underlineSCM(X) ≃ D_sg(X).
ER -