Related papers: Variations on Gravity - Time scales in compact obj…
Gamma-ray Bursts (GRBs) are the most powerful explosions known, capable of outshining the rest of gamma-ray sky during their short-lived prompt emission. Their cosmological nature makes them the best tool to explore the final stages in the…
Gamma-ray bursts (GRBs) are among the most energetic events in the universe, offering insights into stellar collapse, extreme matter behavior, and cosmic evolution. The advent of multi-messenger astronomy, combining electromagnetic,…
The recent confirmation that at least some gamma-ray bursters (GRBs) are indeed at cosmological distances raises the possibility that observations of these could provide interesting constraints on the fundamental laws of physics. Here we…
Gravitational merging (or clustering) of cosmic objects is regarded as a possible source of the extra-acceleration of the universe at large scale. The merging/clustering of cosmic objects introduces a correction term in the equation of…
We describe the model-independent mechanism by which dark matter and dark matter structures heavier than $\sim 8\times 10^{11}$ GeV form binary pairs in the early Universe that spin down and merge both in the present and throughout the…
Nearby, Galactic gamma-ray bursts (GRBs) may affect the terrestrial biota if their radiation is beamed towards the Earth. Compact stellar binary mergers are possible central engines of short GRBs and their rate could be boosted in globular…
We compare the impacts of uncertainties in both binary population synthesis models and the cosmic star formation history on the predicted rates of Gravitational Wave compact binary merger (GW) events. These uncertainties cause the predicted…
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 (GRBs) - short bursts of 100-1MeV photons arriving from random directions in the sky are probably the most relativistic objects discovered so far. Still, somehow they did not attract the attention of the relativistic…
One of the generic predictions of modern cosmological models is that large galaxies should have experienced many mergers with smaller galaxies at some point in their past. Debris from such encounters will leave spatially distinct…
Understanding of the nature of gamma-ray bursts (GRBs) is one of the challenging problem facing the astrophysics community. The field of gamma ray bursts is a rapidly developing one and we expect that new missions, like SWIFT and GLAST will…
Particle acceleration in clusters of galaxies is expected to take place at both merger and accretion shocks. The electron component may be energized to energies of several TeV, and upscatter a small fraction of the photons in the cosmic…
$\gamma$-ray bursts have baffled theorists ever since their accidental discovery at the sixties. We suggest that these bursts originate in merger of neutron star binaries, taking place at cosmological distances. These mergers release…
We study correlations between various hardness ratios of gamma-ray bursts (GRBs) and investigate if there are any differences between the two classes of the objects in the distributions of the ratios. The results suggest that,…
We analyze the randomness of the sky distribution of cosmic gamma-ray bursts. These events are associated with massive galaxies, spiral or elliptical, and therefore their positions should trace the large-scale structure, which, in turn,…
A simple test for time-asymmetry is devised and carried out on the brightest gamma-ray bursts detected by the Burst and Transient Source Experiment (BATSE) on board the {\it Compton} Gamma Ray Observatory. We show evidence that individual…
As the formation of cosmic structure continues to proceed, we observe one of the latest stages of this process in mergers of clusters of galaxies with other clusters, groups, and galaxies. The X-ray emitting hot plasma of these systems can…
Phenomenologically, two classes of GRBs (long/soft vs. short/hard) are identified based on their gamma-ray properties. The boundary between the two classes is vague. Multi-wavelength observations lead to identification of two types of GRB…
A key obstacle to understanding the galaxy merger rate and its role in galaxy evolution is the difficulty in constraining the merger properties and time-scales from instantaneous snapshots of the real universe.The most common way to…
The cosmic gamma-ray burst (GRB) formation rate, as derived from the variability-luminosity relation for long-duration GRBs, is compared with the cosmic star formation rate. If GRBs are related to the collapse of massive stars, one expects…