  We derive a perturbative scheme to treat the interaction between point
sources and AdS-gravity. The interaction problem is equivalent to the search of
a polydromic mapping $X^A= X^A(x^\mu)$, endowed with 0(2,2) monodromies,
between the physical coordinate system and a Minkowskian 4-dimensional
coordinate system, which is however constrained to live on a hypersurface. The
physical motion of point sources is therefore mapped to a geodesic motion on
this hypersuface. We impose an instantaneous gauge which induces a set of
equations defining such a polydromic mapping. Their consistency leads naturally
to the Einstein equations in the same gauge. We explore the restriction of the
monodromy group to O(2,1), and we obtain the solution of the fields
perturbatively in the cosmological constant.
