On class algebras

Abstract

Let F^alpha G be a twisted group algebra.A subalgebra of F^alpha G generated by all class sums ofpartition {mathcal P} of G is called a projective class algebra in F^alpha Gassociated with partition {mathcal P}.In this paperwe study various partitions of G determined by actions of certain operator groups on Gand construct projective class algebras depending on the actions.With regard to projective class algebras,we investigate structures of associated skew group algebras and fixed group algebras.