A Concept of Assessment of LIV Tests with <i>THESEUS</i> Using the Gamma-Ray Bursts Detected by <i>Fermi</i>/GBM

Abstract

According to Einstein’s special relativity theory, the speed of light in a vacuum is constant for all observers. However, quantum gravity effects could introduce its dispersion depending on the energy of photons. The investigation of the spectral lags between the gamma-ray burst (GRB) light curves recorded in distinct energy ranges could shed light on this phenomenon: the lags could reflect the variation of the speed of light if it is linearlydependent on the photon energy and a function of the GRB redshift. We propose a methodology to start investigating the dispersion law of light propagation in a vacuum using GRB light curves. This technique is intended to be fully exploited using the GRB data collected with THESEUS.

Keywords

• gamma-ray bursts
• GRBs as cosmological probes and test-bench for fundamental physics
• GRBs: past, present and future experiments and missions