Jordan *-Derivations on C*-Algebras and JC*-Algebras

Abstract

We investigate Jordan *-derivations on C*-algebras and Jordan *-derivations on JC*-algebras associated with the following functional inequality parallel to f(x) + f(t) + kf(z)parallel to <= parallel to kf((x + y)/k + z)parallel to for some integer k greater than 1. We moreover prove the generalized Hyers-Ulam stability of Jordan *-derivations on C*-algebras and of Jordan *-derivations on JC*-algebras associated with the following functional equation f((x + y)/k + z) = (f(x) + f(y))/k + f(z) for some integer k greater than 1.