The Composition operator on hardy space H2 Induced by φ(z)=sz+t where , and

Abstract

We study in this paper the composition operator of induced by the function φ(z)=sz+t where , and We characterize the normal composition operator Cφ on Hardy space H2 and other related classes of operators. In addition to that we study the essential normality of Cφ and give some other partial results which are new to the best of our knowledge.