Energy-dependent intrinsic time delay of gamma-ray bursts on testing Lorentz invariance violation

TL;DR

This paper investigates whether energy-dependent intrinsic time delays in gamma-ray bursts can explain observed data, testing Lorentz invariance violation and intrinsic emission effects through Bayesian analysis and a unified model.

Contribution

It introduces a comprehensive model combining Lorentz violation and intrinsic delays, reanalyzes GRB data with Bayesian methods, and distinguishes their respective impacts on observed time delays.

Findings

Energy-dependent emission times can explain GRB data.

Intrinsic time delay effects are significant in high-energy photon observations.

Unified model helps separate Lorentz violation effects from intrinsic source delays.

Abstract

High-energy photons of gamma-ray bursts (GRBs) might be emitted at different intrinsic times with energy dependence at the source. In this letter, we expand the model from previous works on testing the Lorentz Invariance Violation (LV) with the observed GRB data from the Fermi Gamma-ray Space Telescope. We reanalyze the previous data with the full Bayesian parameter estimation method and get consistent results by assuming that the time delays are due to an LV term and a constant intrinsic time delay term. Subsequently, we neglect the LV effect and only consider the intrinsic time delay effect. We assume a common intrinsic time delay term along with a source energy correlated time delay of high-energy photons. We find that the energy-dependent emission times can also explain the observed GRB data of high-energy photon events. Finally, we integrate these two physical mechanisms into a unified model to distinguish and evaluate their respective contributions using the observed GRB data.