Constraints on quantum gravity and the photon mass from gamma ray bursts

Abstract

Lorentz Invariance Violation in Quantum Gravity (QG) models or a non-zero photon mass, mγ, would lead to an energy-dependent propagation speed for photons, such that photons of different energies from a distant source would arrive at different times, even if they were emitted simultaneously. By developing source-by-source, Monte Carlo-based forward models for such time delays from Gamma Ray Bursts, and marginalising over empirical noise models describing other contributions to the time delay, we derive constraints on mγ and the QG length scale, QG, using spectral lag data from the BATSE satellite. We find mγ < 4.0 × 10 −5 h eV/c 2 and QG < 5.3 × 10 −18 h GeV −1 at 95% confidence, and demonstrate that these constraints are robust to the choice of noise model. The QG constraint is among the tightest from studies which consider multiple Gamma Ray Bursts and the constraint on mγ, although weaker than from using radio data, provides an independent constraint which is less sensitive to the effects of dispersion by electrons.

A search for the variation of speed of light using galaxy cluster gas mass fraction measurements

“…[56] used a model-independent method to reconstruct the temporal evolution of the speed of light, and the results were in agreement to the value measured at z = 0. Complementary to these tests on the redshift-dependent speed of light, searches for an energy-dependent speed of light (as predicted by certain Lorentz-violating standard model extension models) have also been carried out using spectral lags of Gamma-ray bursts (see [44,57] and references therein).…”