On sandwich theorems for p-valent functions involving a new generalized differential operator

摘要

A new differential operator F(alpha,beta,gamma)(m)f(z) is introduced for functions of the form f (z) = z(P) + Sigma(n=2) (infinity) a(n)z(n) which are p-valent in the unit disk U = {z is an element of C : vertical bar z vertical bar < 1}. The main object of this paper is to derive some subordination and superordination results involving differential operator F(alpha,beta,gamma)(m)f(z).