HOMOMORPHISMS BETWEEN UNITAL C¤¡ALGEBRAS A FIXED POINT APPROACH

Let A;B be two unital C¤¡algebras. By using fixed pint methods, we prove that every almost linear mapping h : A ¡! B which satisfies h(2nuy) = h(2nu)h(y) for all u 2 A+, all y 2 A, and all n = 0; 1; 2; :::, is a homomorphism.