Lorentz invariance violation with gamma rays

TL;DR

This paper discusses testing Lorentz invariance violation using gamma-ray observations, focusing on potential energy-dependent photon dispersion effects and the capabilities of future observatories like the Cherenkov Telescope Array.

Contribution

It explores the possibility of detecting Lorentz invariance violation signatures in gamma-ray lightcurves and evaluates the prospects with upcoming high-energy observatories.

Findings

Potential for LIV detection increases with high-energy, distant gamma-ray sources.

Next-generation telescopes like CTA could improve LIV testing sensitivity.

Energy-dependent photon dispersion could be observable in gamma-ray timing data.

Abstract

The assumption of Lorentz invariance is one of the founding principles of Modern Physics and violation of it would have profound implications to our understanding of the universe. For instance, certain theories attempting a unified theory of quantum gravity predict there could be an effective refractive index of the vacuum; the introduction of an energy dependent dispersion to photons could in turn lead to an observable Lorentz invariance violation signature. Whilst a very small effect on local scales the effect will be cumulative, and so for very high energy particles that travel very large distances the difference in arrival times could become sufficiently large to be detectable. This proceedings will look at testing for such Lorentz invariance violation (LIV) signatures in the astronomical lightcurves of gamma-ray emitting objects, with particular notice being given to the prospects for LIV testing with, the next generation observatory, the Cherenkov Telescope Array.