Classification of a class of torsion-free abelian groups

Abstract

The class of almost completely decomposable groups with a critical typeset of type $(2,2)$ and a regulator quotient of exponent $\le p^2$ is shown to have exactly 4 near-isomorphism classes of indecomposable groups. Every group of the class is up to near-isomorphism uniquely a direct sum of these four indecomposable groups.