English

Toroidal orbifolds, destackification, and Kummer blowings up

Algebraic Geometry 2020-09-23 v1

Abstract

We show that any toroidal DM stack XX with finite diagonalizable inertia possesses a maximal toroidal coarsening XtcsX_{tcs} such that the morphism XXtcsX\to X_{tcs} is logarithmically smooth. Further, we use torification results of [AT17] to construct a destackification functor, a variant of the main result of Bergh [Ber17], on the category of such toroidal stacks XX. Namely, we associate to XX a sequence of blowings up of toroidal stacks F~XYX\widetilde{\mathcal{F}}_X\:Y\longrightarrow X such that YtcY_{tc} coincides with the usual coarse moduli space YcsY_{cs}. In particular, this provides a toroidal resolution of the algebraic space XcsX_{cs}. Both XtcsX_{tcs} and F~X\widetilde{\mathcal{F}}_X are functorial with respect to strict inertia preserving morphisms XXX'\to X. Finally, we use coarsening morphisms to introduce a class of non-representable birational modifications of toroidal stacks called Kummer blowings up. These modifications, as well as our version of destackification, are used in our work on functorial toroidal resolution of singularities.

Keywords

Cite

@article{arxiv.1709.03206,
  title  = {Toroidal orbifolds, destackification, and Kummer blowings up},
  author = {Dan Abramovich and Michael Temkin and Jarosław Włodarczyk},
  journal= {arXiv preprint arXiv:1709.03206},
  year   = {2020}
}

Comments

29 pages

R2 v1 2026-06-22T21:38:33.925Z