English

Fixed point stacks under groups of multiplicative type

Algebraic Geometry 2021-01-08 v1

Abstract

We prove that if a group scheme of multiplicative type acts on an algebraic stack with affine, finitely presented diagonal then the stack of fixed points is algebraic. For this, we extend two theorems of [SGA3.2] on functors of subgroups of multiplicative type, and functors of homomorphisms from a group of multiplicative type.

Keywords

Cite

@article{arxiv.2101.02450,
  title  = {Fixed point stacks under groups of multiplicative type},
  author = {Matthieu Romagny},
  journal= {arXiv preprint arXiv:2101.02450},
  year   = {2021}
}
R2 v1 2026-06-23T21:52:24.643Z