On a class of Butler groups.
On abelian groups by which balanced extensions of a rational group split. II
On Butler -groups decomposing over two base elements
A -group is a sum of a finite number of torsionfree Abelian groups of rank , subject to two independent linear relations. We complete here the study of direct decompositions over two base elements, determining the cases where the relations play an essential role.
On Cartesian Powers of a Rational Group.
On decomposable pseudofree groups.
On Direct Decomposition of Torsion Free Abelian Groups.
On direct decompositions of torsion-free abelian groups of finite rank
On direct sums of -groups
A necessary and sufficient condition is given for the direct sum of two -groups to be (quasi-isomorphic to) a -group. A -group is a torsionfree Abelian group that can be realized as the quotient of a finite direct sum of rank 1 groups modulo a pure subgroup of rank 1.
On direct sums of -groups – II
-groups are a class of torsionfree Abelian groups of finite rank, part of the main class of Butler groups. In the paper C. Metelli, On direct sums of -groups, Comment. Math. Univ. Carolinae 34 (1993), 587–591, the problem of direct sums of -groups was discussed, and a necessary and sufficient condition was given for the direct sum of two -groups to be a -group. While sufficiency holds, necessity was wrongly claimed; we solve here the problem, and in the process study a curious hierarchy among...
On endomorphism algebras over admissible Dedekind domains
On endomorphisms and quasi-endomorphisms of torsionfree groups
On extension of pseudo-integers.
On Fuchs' problem 76.
On purity and quasi-equality of Abelian groups.
On the rings on torsion-free groups
On the subgroups of completely decomposable torsion-free groups that are ideals in every ring
In this paper we consider completely decomposable torsion-free groups and we determine the subgroups which are ideals in every ring over such groups.
On torsion-free periodic rings.
On Virtual Properties and Group Extensions.