The Loewy lenght of tensor products for dihedral two-groups

Abstrakt

The indecomposable modules of a dihedral 2-group over a eld of characteristic 2 were classied by Ringel over 30 years ago. However, relatively little is known about the tensor products of such modules, except in certain special cases.

We describe here the main result of our recent work determining the Loewy length of a tensor product of modules for a dihedral 2-group. As a consequence of this result, we can determine precisely when a tensor product has a projective direct summand.

Klíčová slova

• Loewy
• lenght
• tensor
• products
• for
• dihedral
• two-groups