Centers of -isotypity in abelian groups
Characterization of the inessential endomorphisms in the category of Abelian group.
An endomorphism f of an Abelian group A is said to be inessentia! (in the category of Abelian groups) if it can be extended to an endomorphism of any Abelian group which contains A as a subgroup. In this paper we show that f is as above if and only if (f - v idA)(A) is contained in the rnaximal divisible subgroup of A for some v belonging to Z.
Classification of torsion free abelian minimax groups
Cobalanced exact sequences
Commutative group algebras of highly torsion-complete abelian -groups
A new class of abelian -groups with all high subgroups isomorphic is defined. Commutative modular and semisimple group algebras over such groups are examined. The results obtained continue our recent statements published in Comment. Math. Univ. Carolinae (2002).
Commutativity Criterions using Normal Subgroup Lattices
Completely decomposable pure subgroups of completely decomposable abelian groups