English

Cox rings of algebraic stacks

Algebraic Geometry 2024-01-04 v3

Abstract

We give a proper definition of the multiplicative structure of the following rings: the Cox ring of invertible sheaves on a general algebraic stack; and the Cox ring of rank one reflexive sheaves on a normal and excellent algebraic stack. We show that such Cox rings always exist and establish their (non-)uniqueness in terms of an Ext-group. Moreover, we compare our definition with the classical construction of a Cox ring on a variety. Finally, we give an application to the theory of Mori dream stacks.

Keywords

Cite

@article{arxiv.2004.01445,
  title  = {Cox rings of algebraic stacks},
  author = {Andreas Hochenegger and Elena Martinengo and Fabio Tonini},
  journal= {arXiv preprint arXiv:2004.01445},
  year   = {2024}
}

Comments

23 pages, minor changes. Same content as published version

R2 v1 2026-06-23T14:37:53.616Z