Bending of light in quantum gravity

Niels Emil J. Bjerrum-Bohr (1) , John F. Donoghue (2) , Barry R. Holstein (2) , Ludovic Planté (3) , Pierre Vanhove (3, 4)

1 NBI - Niels Bohr Institute [Copenhagen]
2 UMass Amherst - University of Massachusetts [Amherst]
3 IPHT - Institut de Physique Théorique - UMR CNRS 3681
4 IHES - Institut des Hautes Études Scientifiques

We consider the scattering of light-like matter in the presence of a heavy scalar object (such as the sun or a black hole). By treating general relativity as an effective field theory we directly compute the non-analytic parts of the one-loop gravitational amplitude for the scattering of massless scalars or photons from an external massive scalar field. These results allow a semi-classical computation of the bending angle for light-rays grazing the sun, including long-range ħ contributions. We discuss implications of this computation, in particular the violation of some classical formulations of the equivalence principle.

Domaines: Physique des Hautes Energies - Théorie [hep-th]

Niels Emil J. Bjerrum-Bohr, John F. Donoghue, Barry R. Holstein, Ludovic Planté, Pierre Vanhove. Bending of light in quantum gravity. Physical Review Letters, 2015, 114 (6), pp.061301. ⟨10.1103/PhysRevLett.114.061301⟩. ⟨hal-01078425⟩