2008ApJ...676..532B

The study of time lags between spikes in gamma-ray burst light curves in different energy bands as a function of redshift may lead to the detection of effects due to quantum gravity. We present an analysis of 15 gamma-ray bursts with measured redshift, detected by the HETE-2 mission, in order to measure time lags related to astrophysical effects and search for a quantum gravity signature in the framework of an extradimensional string model. The wavelet transform method is used both for denoising the light curves and for detecting sharp transitions. The use of photon-tagged data allows us to consider various energy ranges and to evaluate systematic effects due to selections and cuts. The analysis of maxima and minima of the light curves leads to no significant quantum gravity effect. A lower limit at the 95% confidence level on the quantum gravity scale parameter of 2x10¹⁵ GeV is set.