International Journal of Mathematics and Mathematical Sciences 
Volume 2006 (2006), Article ID 62548, 6 pages
doi:10.1155/IJMMS/2006/62548

Subordination by convex functions

Rosihan M. Ali, V. Ravichandran, and N. Seenivasagan

School of Mathematical Sciences, Universiti Sains Malaysia (USM), Penang 11800, Malaysia

Received 30 July 2006; Accepted 12 November 2006

Abstract

For a fixed analytic function g(z)=z+n=2gnzn defined on the open unit disk and γ<1, let Tg(γ) denote the class of all analytic functions f(z)=z+n=2anzn satisfying n=2|angn|1γ. For functions in Tg(γ), a subordination result is derived involving the convolution with a normalized convex function. Our result includes as special cases several earlier works.