Quantum corrections to the gravitational potentials of a point source   due to conformal fields in de Sitter
  We derive the leading quantum corrections to the gravitational potentials in a de Sitter background, due to the vacuum polarization from loops of conformal fields. Our results are valid for arbitrary conformal theories, even strongly interacting ones, and are expressed using the coefficients $b$ and $b'$ appearing in the trace anomaly. Apart from the de Sitter generalization of the known flat-space results, we find two additional contributions: one which depends on the finite coefficients of terms quadratic in the curvature appearing in the renormalized effective action, and one which grows logarithmically with physical distance. While the first contribution corresponds to a rescaling of the effective mass, the second contribution leads to a slower fall-off of the Newton potential at large distances, and is potentially measurable. 
Markus B. Fr\"ob, Enric Verdaguer
hep-th gr-qc