Chiral Superfields in IIB Supergravity

The field strength superfield of IIB supergravity on $AdS_5\xz S^5$ is expanded in harmonics on $S^5$ with coefficients which are $D=5, N=8$ chiral superfields. On the boundary of $AdS_5$ these superfields map to $D=4,N=4$ chiral superfields and both sets of superfields obey additional fourth-order constraints. The constraints on the $D=4,N=4$ chiral fields are solved using harmonic superspace in terms of prepotential superfields which couple in a natural way to composite operator multiplets of the boundary $N=4,D=4$ superconformal field theory.