On a Class of Composition Operators on Bergman Space

Let &#x1D53B;={z∈ℂ:|z|<1} be the open unit disk in the complex plane ℂ. Let A2(&#x1D53B;) be the space of analytic functions on &#x1D53B; square integrable with respect to the measure dA(z)=(1/π)dx dy. Given a∈&#x1D53B; and f any measurable function on &#x1D53B;, we define the...

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Bibliographic Details
Main Authors: Namita Das, R. P. Lal, C. K. Mohapatra
Format: Article
Language:English
Published: Hindawi Limited 2007-01-01
Series:International Journal of Mathematics and Mathematical Sciences
Online Access:http://dx.doi.org/10.1155/2007/39819
Description
Summary:Let &#x1D53B;={z∈ℂ:|z|<1} be the open unit disk in the complex plane ℂ. Let A2(&#x1D53B;) be the space of analytic functions on &#x1D53B; square integrable with respect to the measure dA(z)=(1/π)dx dy. Given a∈&#x1D53B; and f any measurable function on &#x1D53B;, we define the function Caf by Caf(z)=f(ϕa(z)), where ϕa∈Aut(&#x1D53B;). The map Ca is a composition operator on L2(&#x1D53B;,dA) and A2(&#x1D53B;) for all a∈&#x1D53B;. Let ℒ(A2(&#x1D53B;)) be the space of all bounded linear operators from A2(&#x1D53B;) into itself. In this article, we have shown that CaSCa=S for all a∈&#x1D53B; if and only if ∫&#x1D53B;S˜(ϕa(z))dA(a)=S˜(z), where S∈ℒ(A2(&#x1D53B;)) and S˜ is the Berezin symbol of S.
ISSN:0161-1712
1687-0425