The generating function of correlators of dual operators on the boundary of
(A)dS4 space corresponding to the conformally coupled ϕ4-model is
obtained up to first order in the coupling constant by using the conformal map
between massless scalar fields in (Euclidean) Minkowski space and conformally
coupled scalars on (Euclidean anti) de Sitter space. Some exact classical
solutions of the nonlinear wave equation of massless (conformally coupled)
ϕ3, ϕ4 and ϕ6-models in D=6,4,3 Euclidean/Minkowski (AdS/dS)
spaces are obtained.Comment: Appendix B including two eps figures is added where the identities
necessary for section 3 are worked out. Furthermore a diagrammatic approach
to calculate higher order terms in the perturbation series is give