PERTURBATIVE QUANTUM-GRAVITY AND NEWTONS LAW ON A FLAT ROBERTSON-WALKER BACKGROUND

We derive the Feynman rules for gravity in the presence of a flat Robe rtson-Walker background and give explicit expressions for the propagat or in the physically interesting cases of inflation, radiation dominat ion, and matter domination. The aforementioned background is generated by a scalar field source which should be taken to be dynamical, As an elementary application, we compute the corrections to the Newtonian g ravitational force in the present matter dominated era and conclude - as expected - that they are negligible except for the largest scales. (C) 1998 Elsevier Science B.V.