ZARM Talk: Probing New Physics with Cherenkov Telescopes
How can we detect tiny hints of new physics in gamma rays from distant galaxies? On May 5 at 14:00, Tomislav Terzić from the University of Rijeka (Croatia) shows how Cherenkov telescopes test for Quantum Gravity effects.
ZARM Talk by Tomislav Terzić | University of Rijeka, Faculty of Physics
- Date: 5 Mai 2025
- Time: 2 pm
- Location: ZARM
Cherenkov telescopes are instruments optimised for detection of very high energy (VHE, E > 100 GeV) gamma rays from astrophysics sources. In addition to astrophysical studies, they play a crucial role in testing possible consequences of Quantum Gravity (QG), such as violation or deformation of Lorentz symmetry. Either of these cases are usually modelled by introducing energy-dependent corrections to the standard photon dispersion relation, which can affect photon propagation speed and interaction. The consequent tiny effects are vastly below sensitivities of present-day laboratories. However, VHE gamma rays, commonly emitted from astrophysical sources, turn out to be excellent probes of QG. Cosmological distances that they cross serve as a natural amplifier for the QG-induced effects. While no deviations from the special relativistic predictions have been detected, strong constraints have been set on modified photon dispersion relations.
In this talk, we will describe the Cherenkov imaging technique, give a general introduction to LIV, review possible effects of LIV on gamma rays, explain the process of testing implications of modified photon dispersion relations, and point out the main difficulties. We will cover different stages from observations, Cherenkov telescopes’ data analysis, statistical methods employed, and finally setting constraints on the QG energy scale. The most recent analysis methods and results will be presented and discussed.
