The optical depth including Lorentz invariance violation energy threshold shifts

Understand

Lorentz invariance violation (LIV) introduced as a generic modification to particle dispersion relations can change the photon energy threshold of pair-production, which modifies the expected gamma-ray flux from astrophysical sources.

• In this work, we review this phenomenon and explore its consequences through the derived effects in the optical depth.
• Then, by looking for subluminal LIV signatures in TeV gamma-ray spectra, we present stringent limits to the LIV energy scale at leading order n=1 and 2.
• And finally, we present the predicted flux of GZK-photons including LIV, in the astrophysical scenario which best describes UHECR data.