Gravitational Rainbow

TL;DR

This paper demonstrates that quadratic gravity causes dispersive photon propagation, leading to an energy-dependent deflection angle of light near the Sun, which could cause a visible spectrum spread.

Contribution

It introduces the concept that quadratic gravity predicts dispersive photon behavior, unlike Einstein's gravity, and calculates the resulting deflection spectrum.

Findings

Photon deflection becomes energy-dependent in quadratic gravity.

The spectrum spread varies with the $R_{ ext{mu nu}}^2$ sector mass.

Potential observable effects on light passing near the Sun.

Abstract

It is shown that unlike Einstein's gravity quadratic gravity produces dispersive photon propagation. The energy-dependent contribution to the deflection of photons passing by the Sun is computed and subsequently the angle at which the visible spectrum would be spread over is plotted as a function of the $R_{\mu\nu}^2-$sector mass.