Automorphisms of Twisted Chevalley Groups of type ${}^2{A}_{\ell }(\ell \ge 5)$ over Local Rings

Abstract

This paper is the first in a series devoted to the classification of automorphisms and isomorphisms of twisted Chevalley groups over commutative rings. In the present paper, we prove that every automorphism of a twisted Chevalley group of type ${}^2{A}_{\ell }$ $(\ell \ge 5)$ over a local ring in which $2$ is invertible is standard.

63 Pages