The Hua operators on homogeneous line bundle on Bounded Symmetric   Domains of Tube Type
  Let D be a bounded symmetric domain of tube type . We show that the image of the Poisson transform on the degenerate principal series representation attached to the Shilov boundary of D is characterized by a covariant differential operator on a homogeneous line bundle on D. 
Abdelhamid Boussejra
math.RT