Light-bending tests of Lorentz invariance

TL;DR

This paper explores how potential local Lorentz violation could alter light bending in weak gravitational fields, providing a framework for testing fundamental physics through solar-system observations.

Contribution

It introduces a modified deflection angle formula incorporating Lorentz violation effects, including anisotropic and Weak Equivalence Principle violations, for analyzing observational data.

Findings

Derived a modified light deflection formula with Lorentz violation effects.

Identified anisotropic effects in light bending absent in General Relativity.

Discussed measurement sensitivities for detecting Lorentz violation in solar-system tests.

Abstract

Classical light bending is investigated for weak gravitational fields in the presence of hypothetical local Lorentz violation. Using an effective field theory framework that describes general deviations from local Lorentz invariance, we derive a modified deflection angle for light passing near a massive body. The results include anisotropic effects not present for spherical sources in General Relativity as well as Weak Equivalence Principle violation. We develop an expression for the relative deflection of two distant stars that can be used to analyze data in past and future solar-system observations. The measurement sensitivities of such tests to coefficients for Lorentz violation are discussed.