Probing Quantum Gravity with Imaging Atmospheric Cherenkov Telescopes

TL;DR

This paper reviews how imaging atmospheric Cherenkov telescopes can test quantum gravity theories, focusing on Lorentz invariance violation, analyzing past methods, results, and future improvements in the field.

Contribution

It provides a comprehensive review of QG effects testable with IACTs, including analysis techniques, historical development, and future research directions.

Findings

Refined analysis methods over two decades.

Constraints on Lorentz invariance violation from IACT data.

Potential improvements for future sensitivity.

Abstract

High energy photons from astrophysical sources are unique probes for some predictions of candidate theories of Quantum Gravty (QG). In particular, imaging atmospheric Cherenkov telescopes (IACTs) are instruments optimised for astronomical observations in the energy range spanning from a few tens of GeV to ~100 TeV, which makes them excellent instruments to search for effects of QG. In this article, we will review QG effects which can be tested with IACTs, most notably the Lorentz invariance violation and its consequences. It is often represented and modelled with photon dispersion relation modified by introducing energy-dependent terms. We will describe the analysis methods employed in the different studies, allowing for careful discussion and comparison of the results obtained with IACTs for more than two decades. Loosely following historical development of the field, we will observe how the analysis methods were refined and improved over time, and analyse why some studies were more sensitive than others. Finally, we will discuss the future of the field, presenting ideas for improving the analysis sensitivity and directions in which the research could develop.