Hilbert-Schmidt Hankel operators on the Bergman space of planar domains

Abstract

In this paper we study the problem of the membership of H ∅ in the Hilbert-Schmidt class, when ∅ ∈ L ∞ (Ω) and Ω is a planar domain. We find a necessary and sufficient condition. We apply this result to the problem of joint membership of Hφ and Hφ̄ in the Hilbert-Schmidt class. Using the notion of Berezin Transform and a result of K. Zhu we are able to give a necessary and sufficient condition. Finally, we recover a result of Arazy, Fisher and Peetre on the case Hφ̄ with φ holomorphic. © 2006 Birkhäuser Verlag Basel/Switzerland.