Journal of Inequalities and Applications 
Volume 2008 (2008), Article ID 859105, 14 pages
doi:10.1155/2008/859105
Research Article

A Class of Integral Operators Preserving Subordination and Superordination

Nak Eun Cho and In Hwa Kim

 Department of Applied Mathematics, Pukyong National University, Pusan 608-737, South Korea
Received 30 October 2007; Accepted 8 January 2008

Recommended by Donal O'Regan

Abstract

We give some subordination- and superordination-preserving properties of certain nonlinear integral operators defined on the space of normalized analytic functions in the open unit disk. The sandwich-type theorems for these integral operators are also obtained. Moreover, we consider an application of the subordination and superordination theorems to the Gauss hypergeometric function.