On Large N Conformal Theories, Field Theories in Anti-De Sitter Space and Singletons

It was proposed by Maldacena that the large $N$ limit of certain conformal field theories can be described in terms of supergravity on anti-De Sitter spaces (AdS). Recently, Gubser, Klebanov and Polyakov and Witten have conjectured that the generating functional for certain correlation functions in conformal field theory is given by the classical supergravity action on AdS. It was shown that the spectra of states of the two theories are matched and the two-point correlation function was studied. We discuss the interacting case and compare the three- and four-point correlation functions computed from a classical action on AdS with the large N limit of conformal theory. We discuss also the large N limit for the Wilson loop and suggest that singletons which according to Flato and Fronsdal are constituents of composite fields in spacetime should obey the quantum Boltzmann statistics.