Self--injective abelian groups
Self-small products of abelian groups
Let and be two abelian groups. The group is called -small if the covariant functor commutes with all direct sums and is self-small provided it is -small. The paper characterizes self-small products applying developed closure properties of the classes of relatively small groups. As a consequence, self-small products of finitely generated abelian groups are described.
Separable mixed groups
Some generalizations of torsion-free Crawley groups
In this paper we investigate two new classes of torsion-free Abelian groups which arise in a natural way from the notion of a torsion-free Crawley group. A group is said to be an Erdős group if for any pair of isomorphic pure subgroups with , there is an automorphism of mapping onto ; it is said to be a weak Crawley group if for any pair of isomorphic dense maximal pure subgroups, there is an automorphism mapping onto . We show that these classes are extensive and pay attention to...
Splitting in abelian groups
Subgroups of the basic subgroup in a modular group ring
Sylow P-Subgroups of Abelian Group Rings
2000 Mathematics Subject Classification: Primary 20C07, 20K10, 20K20, 20K21; Secondary 16U60, 16S34.Let PG be the abelian modular group ring of the abelian group G over the abelian ring P with 1 and prime char P = p. In the present article,the p-primary components Up(PG) and S(PG) of the groups of units U(PG) and V(PG) are classified for some major classes of abelian groups. Suppose K is a first kind field with respect to p in char K ≠ p and A is an abelian p-group. In the present work, the p-primary...