Graviton Propagation and Vacuum Polarization in Curved Space

Abstract

The effects of vacuum polarization arising from loops of massive scalar particles on graviton propagation in curved space are considered. Physically, they are due to curvature induced tidal forces acting on the cloud of virtual scalar particles surrounding the graviton. The effects are tractable in a WKB and large mass limit and the results can be written as an effective refractive index for the graviton modes with both a real and imaginary part. The imaginary part of the refractive index is a curvature induced contribution to the wavefunction renormalization of the graviton in real affine time and can have the effect of dressing or un-dressing the graviton. The real part of the refractive index increases logarithmically at high frequency as long as the null energy condition is satisfied by the background.

21 pages, typos corrected

References in corpus (6)

• Superluminality and UV Completion
• The Refractive Index of Curved Spacetime: the Fate of Causality in QED
• Causality and Micro-Causality in Curved Spacetime
• Fermi Coordinates and Penrose Limits
• The Refractive Index of Curved Spacetime II: QED, Penrose Limits and Black Holes
• The Effect of Gravitational Tidal Forces on Vacuum Polarization: How to Undress a Photon