Robust limits on Lorentz violation from gamma-ray bursts
Abstract
We constrain the possibility of a non-trivial refractive index in free space corresponding to an energy-dependent velocity of light: c( E) ≃ c0(1 - E/ M), where M is a mass scale that might represent effect of quantum-gravitational space-time foam, using the arrival times of sharp features observed in the intensities of radiation with different energies from a large sample of gamma-ray bursters (GRBs) with known redshifts. We use wavelet techniques to identify genuine features, which we confirm in simulations with artificial added noise. Using the weighted averages of the time-lags calculated using correlated features in all the GRB light curves, we find a systematic tendency for more energetic photons to arrive earlier. However, there is a very strong correlation between the parameters characterizing an intrinsic time-lag at the source and a distance-dependent propagation effect. Moreover, the significance of the earlier arrival times is less evident for a subsample of more robust spectral structures. Allowing for intrinsic stochastic time-lags in these features, we establish a statistically robust lower limit: M > 0.9 × 10 16 GeV on the scale of violation of Lorentz invariance.
- Publication:
-
Astroparticle Physics
- Pub Date:
- July 2006
- DOI:
- 10.1016/j.astropartphys.2006.04.001
- arXiv:
- arXiv:astro-ph/0510172
- Bibcode:
- 2006APh....25..402E
- Keywords:
-
- 04.50.+h;
- 04.62.+v;
- 98.80.Cq;
- Gravity in more than four dimensions Kaluza-Klein theory unified field theories;
- alternative theories of gravity;
- Quantum field theory in curved spacetime;
- Particle-theory and field-theory models of the early Universe;
- Astrophysics;
- General Relativity and Quantum Cosmology;
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory
- E-Print:
- 18 pages, 4 eps figures