Related papers: No Evidence of Time Dilation in Gamma-Ray Burst Da…
Context. Explaining the accelerated expansion of the Universe is one of the fundamental challenges in physics today. Cosmography provides information about the evolution of the universe derived from measured distances, assuming only that…
Significant absorption of radiation is usually accompanied by refraction. This is not the case for $\gamma$ rays travelling cosmic distances. We show that the real and imaginary parts of the refraction index are indeed commensurable, as…
Short gamma-ray bursts are believed to originate from the merger of two compact objects. If this scenario is correct, these bursts will be accompanied by the emission of strong gravitational waves, detectable by current or planned GW…
Gamma Ray Bursts (GRB) are among the brightest objects in the Universe and hence can be observed up to a very high redshift. Properly calibrated empirical correlations between intensity and spectral correlations of GRBs can be used to…
Observations of gamma-ray bursts up to $z\sim 9$ are best suited to study the possible evolution of the Universe equation of state at intermediate redshifts. We apply the Combo-relation to a sample of 174 gamma ray bursts to investigate…
Gamma ray burst (GRB) objects are now widely thought to be at cosmological distances, and thus represent enormous energy emission. Gamma ray spectra extending to $GeV$ energies suggest the possiblity of accompanying neutrino emission, and…
Gamma-ray Bursts (GRBs) are bright flashes of high energy photons that can last from about 10 milliseconds to 10 minutes. Their origin and nature have puzzled the scientific community for about 25 years until 1997, when the first X-ray…
We present strong evidence of time stretching in the peak-to-peak time scales in the light curves of BATSE Gamma Ray Bursts (GRBs). Extensive tests are performed on artificially dilated bursts to verify that the procedure for extracting the…
Simultaneous observations by the large number of gamma-ray burst detectors operating in the GLAST era will provide the spectra, lightcurves and locations necessary for studying burst physics and testing the putative relations between…
In this letter, we calculate the redshift distribution of gamma-ray bursts assuming that they trace (i) the globally averaged star formation rate or (ii) the average metallicity in the Universe. While at redshifts 5 and below, both the star…
We review the uncertainties in high-z star-formation rate (SFR) measures and the constraints that one obtains from high-z gamma-ray burst (GRB) rates on them. We show that at the present time, the GRB rates per unit star-formation at z>3…
The observation of the time delay between the soft emission and the high-energy radiation from cosmological gamma ray bursts can be used as an important observational test of multi-dimensional physical theories. The main source of the time…
The prompt emission mechanism of gamma-ray bursts (GRB) even after several decades remains a mystery. However, it is believed that correlations between observable GRB properties given their huge luminosity/radiated energy and redshift…
High-precision cosmological probes have revealed a small but significant tension between the parameters measured with different techniques, among which there is one based on time delays in gravitational lenses. We discuss a new way of using…
Gamma-Ray Bursts (GRBs) are the brightest sources in the universe, emit mostly in the hard X-ray energy band and have been detected at redshifts up to ~8.1. Thus, they are in principle very powerful probes for cosmology. I shortly review…
Due to their extreme luminosities, gamma-ray bursts (GRBs) can be detected in hostile regions of galaxies, nearby and at very high redshift, making them important cosmological probes. The investigation of galaxies hosting long-duration GRBs…
Cosmological gamma ray bursts (GRBs) are the brightest explosions in the Universe. Satellite detectors, such as Beppo-SAX, HETE2 and more recently Swift, have provided a wealth of data, including the localization and redshifts of subsets of…
If gamma-ray bursts have a cosmological origin, the sources are expected to trace the large-scale structure of luminous matter in the universe. I use a new likelihood method that compares the counts-in-cells distribution of gamma-ray bursts…
We test the gamma-ray burst correlation between temporal variability and peak luminosity of the $\gamma$-ray profile on a homogeneous sample of 36 Swift/BAT GRBs with firm redshift determination. This is the first time that this correlation…
One of the cornerstones of modern physics is Einstein's special relativity, with its constant speed of light and zero photon mass assumptions. Constraint on the rest mass m_{\gamma} of photons is a fundamental way to test Einstein's theory,…