Automorphisms of Chevalley groups of types $A_l,D_l,E_l$ 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 $E_l$, $l⩾2$, over a commutative local ring with 1/2 is standard, i. e., is the composition of inner, ring, graph and central automorphisms.

18 pages