Abstract. Let R be a 2-torsion free prime ring, and let J be a nonzero Jordan ideal and a subring of R. In the present paper it is shown that if d is an additive mapping of
IntroductionThroughout this paper R will denote an associative ring with center Z(R). Recall that R is prime if aRb -(0) implies that a = 0 or b = 0. As usual [x, y] and x o y will denote the commutator xy -yx and anticommutator xy + yx, respectively. A ring R is said to be 2-torsion free, if whenever 2x = 0, with x G R, then x = 0. An additive subgroup J of R is said to be a Jordan ideal of R if u o r € J, for all u G J, r € R.
An additive mapping d : R -• R is called a derivation if d(xy) = d(x)y + xd(y), holds for all pairs x, y G R. An additive mapping d : R -> R is called a Jordan derivation if d(x 2 ) = d(x)x + xd(x)holds for all x G R. Obviously, every derivation on a ring R is a Jordan derivation. The converse is, in general, not true. A well known result due to Herstein [6] shows that every Jordan derivation on a 2-torsion free prime ring is a derivation. A brief proof of this result is presented in [4]. This result was generalized by many authors (cf. [5]). In the present paper, our objective is to generalize this result for derivations defined on a subset of a prime rings.
Preliminary resultsTo facilitate our discussion, we introduce abbreviation ¿(x, y) = d(xy) -d(x)y -xd(y). We shall make use of commutator identities: