Search for Lorentz Invariance Violation using Bayesian model comparison applied to Xiao et al. GRB spectral lag catalog

TL;DR

This study uses Bayesian model comparison on a GRB spectral lag catalog to search for Lorentz Invariance violation, finding no evidence but setting lower limits on the LIV energy scale.

Contribution

It introduces an independent Bayesian analysis of GRB spectral lags for LIV, incorporating a non-parametric cosmic expansion model for the first time.

Findings

No evidence for LIV was found.

Lower limits on LIV energy scale: $4 imes 10^{15}$ GeV (linear), $6.8 imes 10^{9}$ GeV (quadratic).

Results are consistent across different cosmic expansion models.

Abstract

We use the spectral lag catalog of 46 short GRBs aggregated by Xiao et al (2022), to carry out an independent search for Lorentz Invariance violation (LIV). For this purpose, we use a power-law model as a function of energy for the intrinsic astrophysical induced spectral lags. The expansion history of the universe needed for constraining LIV was obtained in a non-parametric method using cosmic chronometers. We use Bayesian model comparison to determine if the aforementioned spectral lags show evidence for LIV as compared to only astrophysically induced lags. We do not find any evidence for LIV, and obtain 95\% c.l. lower limits on the corresponding energy scale to be $4 \times 10^{15}$ GeV and $6.8 \times 10^{9}$ GeV for the linear and quadratic LIV models respectively. Our results obtained by using the flat $\Lambda$CDM model for characterizing the cosmic expansion history are consistent with those obtained using chronometers.