A theorem on the order of automorphisms of finite p-groups

Abstract

N. Blackburn proved the following: Let G be a finite p-group and let E be a subgroup which is abelian of exponent at most p^n \u3e 2 and is maximal subject to these restrictions. Let a be an automorphism of G which leaves each element of E invariant. Then the order of a is a power of p. This paper is concerned with presenting a detailed proof of this result by Blackburn. Supporting lemmas nad definitions are included in this paper. Results by W. Feit, J. Thompson and B. Huppert are presented as immediate consequences of Blackburn\u27s theorem