Automorphisms of Chevalley groups of types $A_l, D_l, E_l$ over local rings with 1/2

TL;DR

This paper proves that all automorphisms of elementary Chevalley groups of types A_l, D_l, E_l over local rings with 1/2 are standard, composed of known automorphism types, extending understanding of their symmetry structures.

Contribution

It establishes that every automorphism of these Chevalley groups over such rings is standard, confirming their automorphism groups are generated by inner, ring, graph, and central automorphisms.

Findings

All automorphisms are standard

Automorphism groups are generated by known automorphisms

Extends classification to Chevalley groups over local rings with 1/2

Abstract

In the paper we prove that every automorphism of a (elementary) Chevalley group of type $A_l, D_l$, or $E_l$, $l\geqslant 2$, over a commutative local ring with 1/2 is standard, i. e., is the composition of inner, ring, graph and central automorphisms.