On covers of abelian groups by cosets
On D'Alembert's functional equation on a Abelian group.
On decomposable fully transitive torsion-free groups.
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 Summands of A-Separable R-Modules.
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 duality of submodule lattices
An elementary proof is given for Hutchinson's duality theorem, which states that if a lattice identity λ holds in all submodule lattices of modules over a ring R with unit element then so does the dual of λ.
On elementary equivalence of abelian groups
On elongations of totally projective -groups by -projective -groups
On endomorphism algebras over admissible Dedekind domains
On Endomorphism Rings of Primary Abelian Groups.
On endomorphisms and quasi-endomorphisms of torsionfree groups
On Erdős-Ginzburg-Ziv inverse theorems
On extending functions to solutions of some functional equations.
On extending functions to solutions of some functional equations. (Short Communications).
On extension of pseudo-integers.
On extensions of bounded subgroups in Abelian groups
It is well-known that every bounded Abelian group is a direct sum of finite cyclic subgroups. We characterize those non-trivial bounded subgroups of an infinite Abelian group , for which there is an infinite subgroup of containing such that has a special decomposition into a direct sum which takes into account the properties of , and which induces a natural decomposition of into a direct sum of finite subgroups.