Gerbes for trigonalizable group schemes

Noah Olander; Martin Olsson

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arXiv · 2508.21218

Gerbes for trigonalizable group schemes

Noah Olander·Martin Olsson

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Abstract

We prove that smooth, separated Deligne--Mumford stacks in mixed characteristic with quasi-projective coarse moduli space are global quotient stacks and satisfy the resolution property. This builds on work of Kresch and Vistoli and of Bragg, Hall, and Matthur which proves the case when the stack is over a base field, as well as work of Gabber and de Jong which proves the same holds for a $\mu_n$-gerbe over a scheme with an ample line bundle. The key technical input is a result that gerbes banded by so-called trigonalizable group schemes admit faithful vector bundles and are quotient stacks.

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BibTeX RIS

Noah Olander, Martin Olsson. 2025-08-28. Gerbes for trigonalizable group schemes. https://arxiv.org/abs/2508.21218

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