PORTUGALIAEMATHEMATICA
Vol. 59, No. 3, pp. 325-333 (2002)
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PORTUGALIAE MATHEMATICA Vol. 59, No. 3, pp. 325-333 (2002) |
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Caractérisation des Automorphismes d'un Groupe Abélien ayant la Propriété de l'ExtensionS. Abdelalim and H. EssannouniUniversité 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
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