Possible quantum gravity effects on the gravitational deflection of light

TL;DR

This paper explores potential quantum gravity effects on light deflection by proposing two spacetime deformations, deriving their impact on deflection angles, and suggesting observational methods to distinguish these effects.

Contribution

It introduces two novel models of quantum gravity effects on Schwarzschild spacetime and derives their implications for light deflection angles.

Findings

QG effects modify light deflection angles.

Weak and strong QG effects are modeled with different spacetime deformations.

Vacuum energy density relates to spacetime deformation parameter.

Abstract

We investigate possible quantum gravity (QG) effects on the gravitational deflection of light. Two forms of deformation of the Schwarzschild spacetime are proposed. The first ansatz is a given Finslerian line element, it could be regarded as a weak QG effect on the Schwarzschild spacetime. Starting from this ansatz, we deduce the deflection angle of the light ray which passes a weak gravitational source. The second ansatz could be regarded as a strong QG effect on the Schwarzschild spacetime. The deflection angle of the light ray which passes a weak gravitational source is deduced in this Riemannian spacetime. This QG effect may distinguish the mixed light rays in the absence of gravitational source by a "spectroscope" (the gravitational source). The solutions of gravitational field equation in this Riemannian spacetime indicate that the QG effect could be regarded as the vacuum energy and the energy density of vacuum is related to the spacetime deformation parameter.