Symmetric subgroups of gauged supergravities and AdS string theory vertex operators

We show how the gauge symmetry representations of the massless particle con tent of gauged supergravities that arise in the AdS/CFT correspondences can be derived from symmetric subgroups to be carried by string theory vertex operators, although explicit vertex operator constructions of the IIB strin g on AdS remain elusive. Our symmetry mechanism parallels the construction of representations of the Monster group and affine algebras in terms of twi sted conformal field theories, and may serve as a guide to a perturbative d escription of the IIB string on AdS.