Abstract
We consider the graviton propagator in a de Sitter background. The propagator depends upon the choice of a gauge-fixing term , and we consider the ‘‘ε gauges’’ with =(-ε). We show that the propagator is completely finite and has no infrared divergences provided that ε is not given certain ‘‘exceptional’’ values. It is only for these ‘‘exceptional’’ values of ε that the propagator has an infrared divergence. We then show that in these exceptional cases the divergences are gauge artifacts and are not physical: they make no contribution to any physical tree-level scattering amplitudes. Furthermore, we show that at one-loop order the zero modes which arise (only) if ε is given one of the exceptional values are canceled by the Faddeev-Popov ghosts. There is thus no evidence that the de Sitter background is inconsistent when gravitational fluctuations are considered.
- Received 30 June 1986
DOI:https://doi.org/10.1103/PhysRevD.34.3670
©1986 American Physical Society