Portugaliae Mathematica   EMIS ELibM Electronic Journals PORTUGALIAE
MATHEMATICA
Vol. 59, No. 3, pp. 325-333 (2002)

Previous Article

Next Article

Contents of this Issue

Other Issues


ELibM Journals

ELibM Home

EMIS Home

 

Caractérisation des Automorphismes d'un Groupe Abélien ayant la Propriété de l'Extension

S. Abdelalim and H. Essannouni

Université Mohammed V, Faculté des Sciences, Dép. de Mathématiques et Informatique,
B.P. 1014. Rabat -- MOROCCO
E-mail: seddikabd@hotmail.com , esanouni@fsr.ac.ma

Abstract: In this paper we show that an automorphism $\alpha$ of an abelian group $A$ can be extented to an automorphism of any abelian group which contains $A$ as subgroup iff $(\alpha-id_A)(A)$ or $(\alpha+id_A)(A)$ is a divisible subgroup of $A$. Then if $A$ is reduced, $id_A$ and $-id_A$ are the only automorphisms of $A$ which have the extension property.

Full text of the article:


Electronic version published on: 9 Feb 2006. This page was last modified: 27 Nov 2007.

© 2002 Sociedade Portuguesa de Matemática
© 2002–2007 ELibM and FIZ Karlsruhe / Zentralblatt MATH for the EMIS Electronic Edition