Constraining the curvature-induced quantum gravity scales via gamma-ray bursts

TL;DR

This paper uses gamma-ray burst observations to set observational limits on curvature-induced quantum gravity effects, constraining their energy scales and exploring potential signatures of quantum gravity in high-energy astrophysical phenomena.

Contribution

It provides the first observational constraints on curvature-induced quantum gravity time-of-flight effects using GRB data, establishing lower bounds on the quantum gravity energy scale.

Findings

Lower limit of approximately 10 times the Planck energy on quantum gravity effects.

Curvature-induced effects may only occur above 0.04 times the Planck energy.

Current observations are unlikely to significantly improve these constraints.

Abstract

We constrain the parameters that govern curvature-induced quantum gravity time-of-flight (TOF) effects. These TOF delays, which occur due to modified dispersion relations of particles in the vacuum, could be a phenomenological signature of quantum gravity. Gamma-ray bursts (GRBs), short, high-energy events from distant galaxies, offer a unique opportunity to impose observational limits on TOF delays and, by extension, on the energy scales of quantum gravity. Using the standard Jacob-Piran relation, which assumes a locally-flat spacetime, the analysis of quantum gravity-induced TOF effects establishes a lower limit of approximately $10 E_{\rm Pl}$ on the energy scale of these effects. However, curvature-induced quantum gravity effects may introduce additional contributions. From current GRB observations, we find that, at a 95% credibility level, in the symmetry-deformed scenario, curvature-induced TOF effects may only arise at energies above $0.04 E_{\rm Pl}$. If we consider only curvature-induced effects, this limit is an order of magnitude stronger. Observing more GRBs at different redshifts could improve the constraints on the curvature-induced QG phenomena. However, given the capabilities of current telescopes and the current understanding of GRBs, it is unlikely that these constraints will be significantly extended beyond the present level.