On subordination-preserving theorem

摘要

Let H denote the class of analytic functions in the unit disc on the complex plane C. If the operator I:H→H satisfiesf(z)≺g(z)⇒I[f](z)≺I[g](z)for all f,g∈H, then it is called subordination-preserving operator on the class H. In this paper we present a new result of this form which generalize some of the earlier and is connected with the Wilf’s conjecture. The applications of main result are also presented.