On the subgroups of completely decomposable [4pt] torsion-free groups that are ideals [4pt] in every ring

A. M. Aghdam, F. Karimi, and A. Najafizadeh

Address:
Department of Mathematics, University of Tabriz, Tabriz, Iran
Department of Mathematics, University of Tabriz, Tabriz, Iran
Mathematics Department, Payame Noor University, 19395-4697, Tehran, I.R. of IRAN

E-mail:
mehdizadeh@tabrizu.ac.ir
karimi@tabrizu.ac.ir
ar_najafizadeh@yahoo.com

Abstract: In this paper we consider completely decomposable torsion-free groups and we determine the subgroups which are ideals in every ring over such groups.

AMSclassification: primary 20K15.

Keywords: completely decomposable group, type, ring.

DOI: 10.5817/AM2012-2-107