Graded blocks of group algebras with dihedral defect groups
Volume 122 / 2011
Colloquium Mathematicum 122 (2011), 149-176
MSC: Primary 16W50; Secondary 20C20, 18E30.
DOI: 10.4064/cm122-2-1
Abstract
We investigate gradings on tame blocks of group algebras whose defect groups are dihedral. For this subfamily of tame blocks we classify gradings up to graded Morita equivalence, we transfer gradings via derived equivalences, and we check the existence, positivity and tightness of gradings. We classify gradings by computing the group of outer automorphisms that fix the isomorphism classes of simple modules.
