LQG-modified dispersion relations and the problem of cosmic photons threshold anomalies

Abstract

Our present contribution sets out to investigate how combined effects of Lorentz invariance violation (LIV) and loop quantum gravity (LQG)-modified photon dispersion relations affect the threshold anomaly of cosmic photons. The point of departure is the post-Maxwellian version of electromagnetism induced by LQG effects. We then consider the problem of gamma-ray attenuation by the extragalactic background light (EBL) and the cosmic microwave background radiation (CMB) dominated by the Breit-Wheeler Effect. By following this path, we aim at the establishment of a new bridge between LIV and astrophysical phenomena in the framework of LQG, providing a robust explanation for recent ultra high energy (UHE) astrophysical observations.

27 pages, 2 figures