Dual dimension of modules over normalizing extensions.
Let S = Σ Ra be a finite normalizing extension of R and suppose that M is a left S-module. Denote by crk(A) the dual Goldie dimension of the module A. We show that crk(M) ≤ n · crk(M) if either M is artinian or the group homomorphism M → aM given by x → ax is an isomorphism.