English

On stacky surfaces and noncommutative surfaces

Algebraic Geometry 2024-02-09 v2 Rings and Algebras Representation Theory

Abstract

Let k\mathbf{k} be an algebraically closed field of characteristic 7\geq 7 or zero. Let A\mathcal{A} be a tame order of global dimension 22 over a normal surface XX over k\mathbf{k} such that Z(A)=OX\operatorname{Z}(\mathcal{A})=\mathcal{O}_{X} is locally a direct summand of A\mathcal{A}. We prove that there is a μN\mu_N-gerbe X\mathcal{X} over a smooth tame algebraic stack whose generic stabilizer is trivial, with coarse space XX such that the category of 1-twisted coherent sheaves on X\mathcal{X} is equivalent to the category of coherent sheaves of modules on A\mathcal{A}. Moreover, the stack X\mathcal{X} is constructed explicitly through a sequence of root stacks, canonical stacks, and gerbes. This extends results of Reiten and Van den Bergh to finite characteristic and the global situation. As applications, in characteristic 00 we prove that such orders are geometric noncommutative schemes in the sense of Orlov, and we study relations with Hochschild cohomology and Connes' convolution algebra.

Keywords

Cite

@article{arxiv.2206.13359,
  title  = {On stacky surfaces and noncommutative surfaces},
  author = {Eleonore Faber and Colin Ingalls and Shinnosuke Okawa and Matthew Satriano},
  journal= {arXiv preprint arXiv:2206.13359},
  year   = {2024}
}

Comments

v2:many minor revisions. Section 6 of v1 is removed. 34 pages

R2 v1 2026-06-24T12:05:28.967Z