Splitting mixed groups of torsion-free finite rank II.
Hokkaido Mathematical Journal, 42 (2013) pp.331-343
First we introduce the concept of QD-hulls in arbitrary abelian groups. Then we use the concept to give a new characterization of purifiable torsion-free finite rank subgroups of an arbitrary abelian group. Finally we use it to formulate a splitting criterion for mixed groups of torsion-free finite rank.
|Uncontrolled Keywords||Splitting mixed group, QD-hull, purifiable subgroup, vertical subgroup, N-high subgroup, n-th p-overhang|