Derivations of graded rings and Clifford systems (Q1071094)

Let G be a finitely generated abelian group and let R be a ring which is strongly graded by G. A Clifford system is an epimorphic image of such a graded ring. In the first part of this paper, the author gives general results on derivations of graded rings. In the second section, he relates the derivations of a Clifford system with Galois cohomology of the grading group G. This approach has applications in the theory of crossed products for Azumaya algebras.