Gravitational time delay of light for various models of modified gravity

TL;DR

This paper investigates how different modified gravity models affect the gravitational time delay of light, proposing that precise measurements could distinguish between these models in the solar system.

Contribution

It clarifies the dependence of light's time delay on various modified gravity models and suggests experimental setups to differentiate these models.

Findings

Time delay varies with different modified gravity models

Radio signals and laser interferometry can probe these effects

Potential to test gravity theories within the solar system

Abstract

We reexamined the gravitational time delay of light, allowing for various models of modified gravity. We clarify the dependence of the time delay (and induced frequency shift) on modified gravity models and investigate how to distinguish those models, when light propagates in static spherically symmetric spacetimes. Thus experiments by radio signal from spacecrafts at very different distances from Sun and future space-borne laser interferometric detectors could be a probe of modified gravity in the solar system.