Dual amplitudes constructed on J>0 integer point SU$_{1,1}$ representations

One studies the possibility of constructing factorizable dual amplitudes based on positive integer point SU/sub 1,1/ representations. The (2J+1) invariant subspace in D/sup (x)/ leads in this case to a (2J+1)-dimensional generalized zero mode that can be interpreted in terms of an internal spin of the ground state. Typically, Born-term amplitudes constructed in this manner will exhibit multipole ghosts on nonleading levels. A divergence is also present at the Born-term level. It is suggested that these models can also be formulated as Lagrangian field theories on a two-dimensional manifold. This may yield a way of formulating auxiliary conditions and investigating whether the state vector space can be divided in physical and nonphysical sectors. (9 refs).