English

Algebraicity and smoothness of fixed point stacks

Algebraic Geometry 2022-09-19 v3

Abstract

We study algebraicity and smoothness of fixed point stacks for flat group schemes which have a finite composition series whose factors are either reductive or proper, flat, finitely presented, acting on algebraic stacks with affine, finitely presented diagonal. For this, we extend some theorems of [SGA3.2] on functors of homomorphisms Hom(G, H) and functors of reductive subgroups Sub(H) for an affine, possibly non-flat group scheme H.

Keywords

Cite

@article{arxiv.2205.11114,
  title  = {Algebraicity and smoothness of fixed point stacks},
  author = {Matthieu Romagny},
  journal= {arXiv preprint arXiv:2205.11114},
  year   = {2022}
}

Comments

Added ''main ideas of the proofs'' in the introduction and corrected typos