THE COMPACT OF THE COMPOSITION OPERATOR

Abstract

Let U denote the unit ball in the complex plane, the Hardy space is the set of functions holomorphic on U such that with denotes the Taylor coefficient of f . Let  be a holomorphic self-map of U, the composition operator induced by  is defined on by the equation We have studied the composition operator induced by the bijective map  and discussed the adjoint of the composition operator .We have look also at some known properties of composition operator and tried to get the analogue properties in order to show how the results are changed by changing the map  in U. In order to make the work accessible to the reader , we have included some known results with the details of the proofs for some cases and proved some results.