Abstract
In the present paper we study the operator defined by using the Ruscheweyh derivative Rm f(z) and the S?l?gean operator Sm f(z), denoted Lm? : An ? An, Lm? f(z) = (1??)Rm f(z)+?Sm f(z), z ? U, where An = {f ? H(U) : f(z) = z+an+1zn+1+. . . , z ? U} is the class of normalized analytic functions. We obtain several differential subordinations regarding the operator Lm?.