LINEAR JORDAN DERIVATIONS ON NONCOMMUTATIVE BANACH ALGEBRAS

The purpose of this paper is to prove the following result: Let A be a noncom mutative Banach algebra. Suppose that there exist continuous linear Jordan derivations $D:A{\rightarrow}A$, $G:A{\rightarrow}A$ such that [$D^2(x)+G(x)$, $x^n$] lies in the Jacobson radical of A for all $x{\in}A$. Then $D(A){\subset}rad(A)$ and $G(A){\subset}rad(A)$.