On certain quotients of the Green rings of dihedral 2-groups

In this paper we study the properties of Green rings of dihedral 2-groups, and in particular certain quotients of these Green rings introduced by Benson and Carlson. It is shown that these quotients can be realised as group rings over ZZ. The properties of the corresponding groups are investigated: they are shown to be abelian, torsion-free and infinitely generated. We also show how taking products of elements of these groups is related to the structure of the Auslander–Reiten quivers for dihedral 2-groups.