Gravitational lensing time delays as a tool for testing Lorentz Invariance Violation

TL;DR

This paper proposes using gravitational lensing time delays across different photon energies to test for Lorentz Invariance Violation, offering a new method less affected by systematic uncertainties.

Contribution

It introduces a novel approach to test LIV by analyzing energy-dependent gravitational lensing time delays, reducing systematic errors present in previous methods.

Findings

Potential to detect LIV-induced delays in astrophysical observations

Method reduces systematic uncertainties compared to other LIV tests

Provides a new observational strategy for quantum gravity effects

Abstract

Despite the fact that quantum gravity theory still remains elusive, it is generally expected that it will bring the picture of a space-time foam at short distances leading to Lorenz Invariance Violation (LIV) manifested e.g. by energy dependent modification of standard relativistic dispersion relation. One direction of research, pursued intensively is to measure energy dependent time of arrival delays in photons emitted by astrophysical sources located at cosmological distances. This is tempered however by our ignorance of either intrinsic delay (at source frame) in different energy channels or as recently shown, the correct model of the background cosmology. In this paper we propose a new test based on gravitational lensing. Monitoring time delays between images performed in different energy channels (e.g. optical - low energy and TeV photons) may reveal extra delays due to distorted dispersion relation typical in LIV theories - a test which is free from the systematics inherent in other settings.