Related papers: Robust Limits on Lorentz Violation from Gamma-Ray …
The fast temporal structures and cosmological distances of gamma-ray bursts (GRBs) afford a natural laboratory for testing theories of frequency-dependent propagation of high-energy photons, as predicted for quantum gravity (QG). We…
We calculate the expected envelope of emission for relativistic shells under the assumption of local spherical symmetry. Gamma-Ray Burst envelopes rarely conform to the expected shape, which is similar to a FRED; a fast rise and exponential…
Relations between the observed quantities for a beamed radio jet, apparent transverse speed and apparent luminosity (beta_app,L), and the intrinsic quantities, Lorentz factor and intrinsic luminosity (gamma,L_o), are investigated. The…
We present a unified general formalism for ultraviolet Lorentz invariance violation (LV) testing through electromagnetic wave propagation, based on both dispersion and rotation measure data. This allows for a direct comparison of the…
Sudden collapse of a compact object, or coalescence of a compact binary, can generate an unsteady relativistic wind that lasts for a few seconds. The wind is likely to carry a high magnetic field; and its Lorentz factor depends on the…
The study of time lags between spikes in Gamma-Ray Bursts 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…
We have developed a computer model to calculate gamma ray burst (GRB) light curves and efficiencies from the interaction of a single, thin blast wave with clouds in the external medium. Large amplitude, spiky variability occurs when the…
Gamma ray bursts (GRBs) are known to have short-time variability and power-law behavior with the index -1.67 in the power spectrum density. Reanalyzing the expanded data, we have found a) the power-law comes from the global profile of the…
The analysis of spectral lag between energy bands, which combines temporal and spectral analyses, can add strict constraints to gamma-ray burst (GRB) models. In previous studies, the lag analysis focused on the lags between channel 1 (25-57…
The rapid variability observed in very-high-energy (VHE) sources-such as pulsars, gamma-ray bursts (GRBs), and flares from active galactic nuclei (AGN)-can be used to detect or constrain a potential violation of Lorentz invariance (LIV).…
We investigate, independently of specific emission models, the constraints on the value of the bulk Lorentz factor Gamma of a fireball. We assume that the burst emission comes from internal shocks in a region transparent to Thomson…
The nature of Gamma Ray Bursts (GRBs) remains a complete mystery, despite the recent breakthrough discovery of low energy counterparts, although it is now generally believed that at least most GRBs are at cosmological distances. Virtually…
We constrain the minimum variability timescales for 938 GRBs observed by the Fermi/GBM instrument prior to July 11, 2012. The tightest constraints on progenitor radii derived from these timescales are obtained from light curves in the…
Lorentz Invariance Violation (LIV) may be a good observational window on Quantum Gravity physics. Within last few years, all major Gamma-ray experiments have published results from the search for LIV with variable astrophysical sources:…
We calculate the synchrotron self-Compton emission from internal shocks occurring in relativistic winds as a source of gamma-ray bursts, with allowance for self-absorption. For plausible model parameters most pulses within a Gamma-Ray Burst…
We have performed searches for isolated flares and for steady flickering in Gamma Ray Burst light curves on the microsecond to millisecond time scales. Two bursts out of our sample of 20 revealed four isolated flares with time scales from…
The onset of GRB afterglow is characterized by a smooth bump in the early afterglow lightcurve. We make an extensive search for such a feature. Twenty optically selected GRBs and 12 X-ray selected GRBs are found, among which 17 optically…
Einstein's equivalence principle (EEP) can be tested by the time delay between photons with different energies passing through a gravitational field. As one of the most energetic explosions in the Universe, gamma-ray bursts (GRBs) provide…
Current limits on violation of local Lorentz invariance in the photon sector are derived mainly from experiments that search for a spatial anisotropy in the speed of light. The presently operating gravitational wave detectors are Michelson…
Several interesting luminosity correlations among gamma-ray burst (GRB) variables have been recently discussed extensively. In this paper, we derive the six luminosity correlations ($\tlag-L$, $V-L$, $\epkk-L$, $\epkk-E_\gamma$, $\trt-L$,…