Quantumgravity analysis of gammaray bursts using wavelets
Abstract
In some models of quantum gravity, spacetime is thought to have a foamy structure with nontrivial optical properties. We probe the possibility that photons propagating in vacuum may exhibit a nontrivial refractive index, by analyzing the times of flight of radiation from gammaray bursters (GRBs) with known redshifts. We use a wavelet shrinkage procedure for noise removal and a wavelet ``zoom'' technique to define with high accuracy the timings of sharp transitions in GRB light curves, thereby optimizing the sensitivity of experimental probes of any energy dependence of the velocity of light. We apply these wavelet techniques to 64 ms and TTE data from BATSE, and also to OSSE data. A search for time lags between sharp transients in GRB light curves in different energy bands yields the lower limit M >=6.9 x 10^{15} GeV on the quantumgravity scale in any model with a linear dependence of the velocity of light ~ E/M. We also present a limit on any quadratic dependence.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 May 2003
 DOI:
 10.1051/00046361:20030263
 arXiv:
 arXiv:astroph/0210124
 Bibcode:
 2003A&A...402..409E
 Keywords:

 distance scale;
 gamma ray: bursts;
 methods: statistical;
 Astrophysics;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Phenomenology;
 High Energy Physics  Theory
 EPrint:
 This version is accepted for publication in Astronomy &