Automorphisms of Chevalley groups over commutative rings
Group Theory
2023-06-06 v2 Rings and Algebras
Abstract
In this paper we prove that every automorphism of a Chevalley group (or its elementary subgroup) with root system of rank >1 over a commutative ring (with 1/2 for the systems A_2, F_4, B_l, C_l; with 1/2 and 1/3 for the system G_2) is standard, i.e., it is a composition of ring, inner, central and graph automorphisms. This result finalizes description of automorphisms of Chevalley groups. However the restrictions on invertible elements can be a topic of further considerations. We provide also some model-theoretic applications of this description.
Keywords
Cite
@article{arxiv.2304.13447,
title = {Automorphisms of Chevalley groups over commutative rings},
author = {Elena Bunina},
journal= {arXiv preprint arXiv:2304.13447},
year = {2023}
}
Comments
22 pages, 1 figure. arXiv admin note: text overlap with arXiv:1108.0529, arXiv:2304.06259