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Journal of Functional Analysis 236 (2006) 546–580<br />

www.elsevier.com/locate/jfa<br />

Hua operators and Poisson transform for boun<strong>de</strong>d<br />

symmetric domains ✩<br />

Khalid Koufany a , Genkai Zhang b,∗<br />

a Institut Élie Cartan, UMR 7502, Université Henri Poincaré (Nancy 1), BP 239,<br />

F-54506 Vandœuvre-lès-Nancy ce<strong>de</strong>x, France<br />

b Department of Mathematics, Chalmers University of Technology and Göteborg University,<br />

S-41296 Göteborg, Swe<strong>de</strong>n<br />

Received 8 December 2005; accepted 24 February 2006<br />

Avai<strong>la</strong>b<strong>le</strong> online 4 April 2006<br />

Communicated by Paul Malliavin<br />

Abstract<br />

Let Ω be a boun<strong>de</strong>d symmetric domain of non-tube type in Cn with rank r and S its Shilov boundary. We<br />

consi<strong>de</strong>r the Poisson transform Psf(z)for a hyperfunction f on S <strong>de</strong>fined by the Poisson kernel Ps(z, u) =<br />

(h(z, z) n/r /|h(z, u) n/r | 2 ) s , (z, u)×Ω ×S, s ∈ C.Forallssatisfying certain non-integral condition we find<br />

a necessary and sufficient condition for the functions in the image of the Poisson transform in terms of Hua<br />

operators. When Ω is the type I matrix domain in Mn,m(C) (n m), we prove that an eigenvalue equation<br />

for the second or<strong>de</strong>r Mn,n-valued Hua operator characterizes the image.<br />

© 2006 Elsevier Inc. All rights reserved.<br />

Keywords: Boun<strong>de</strong>d symmetric domains; Shilov boundary; Invariant differential operators; Eigenfunctions; Poisson<br />

transform; Hua systems<br />

1. Intro<strong>du</strong>ction<br />

Let Ω = G/K be a Riemannian symmetric space. Any parabolic subgroup P of G <strong>de</strong>fines a<br />

boundary G/P of the symmetric space Ω. The Poisson transform is an integral operator from<br />

hyperfunctions on G/P into the space of eigenfunctions on Ω of the algebra D(Ω) G of invariant<br />

✩ Research of the authors is partly supported by European IHP network Harmonic Analysis and Re<strong>la</strong>ted Prob<strong>le</strong>ms.<br />

Research of G. Zhang is supported by Swedish Science Council (VR).<br />

* Corresponding author.<br />

E-mail addresses: khalid.koufany@iecn.u-nancy.fr (K. Koufany), genkai@math.chalmers.se (G. Zhang).<br />

0022-1236/$ – see front matter © 2006 Elsevier Inc. All rights reserved.<br />

doi:10.1016/j.jfa.2006.02.014

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