  In this paper we study intertwining functors (Radon transforms) for twisted
D-modules on partial flag varieties and their relation to the representations
of semisimple Lie algebras. We show that certain intertwining functors give
equivalences of derived categories of twisted D-modules. This is a
generalization of a result by Marastoni. We also show that these intertwining
functors from dominant to antidominant direction are compatible with taking
global sections.
