Document Type : Research Paper
Khayyam Higher Education Institute, Mashhad , Iran
Department of Pure Mathematics, Faculty of Mathematical Sciences, Ferdowsi University of Mashhad, P.O. Box 1159, Mashhad, Iran
Let W be a non-empty subset of a free group. The automorphism
of a group G is said to be a marginal automorphism, if for all x in G,
x^−1alpha(x) in W^*(G), where W^*(G) is the marginal subgroup of G.
In this paper, we give necessary and sufficient condition for a purely
non-abelian p-group G, such that the set of all marginal automorphisms
of G forms an elementary abelian p-group.