Department of Mathematics, Shiraz University, Shiraz 71454, Iran ; Department of Mathematics, Yazd University, Yazd, Iran
Abstract:
Let be a certain Banach space consisting of continuous functions defined on the open unit disk. Let be a univalent function defined on , and assume that denotes the operator of multiplication by . We characterize the structure of the operator such that . We show that for some function in . We also characterize the commutant of under certain conditions.