Related papers: Possible Alternate Scenario for short Duration GRB…

Primordial black holes have been considered as an attractive dark matter candidate, whereas some of the predictions heavily rely on the near-horizon physics that remains to be tested experimentally. As a concrete alternative, thermal…

Strange Quark Nuggets are the relics of the microsecond old universe after the big bang. The universe having experienced a mini inflation of 7-e folding has gone through supercooling leading to a first order phase transition from quark to…

High energy gamma-rays and neutrinos can be produced both by the annihilation and by the possible slow decay of dark matter particles. We discuss the fluxes and spectra of such secondaries produced by dark matter particles in the universe…

This paper reviews the X-ray, optical, radio and IR observations of galactic X-ray binaries suspected to contain black hole compact objects, with particular emphasis on the supporting dynamical evidence.

If we consider the gravitational collapse of a material object to a black hole, we would expect, for ranges of mass where a black hole would form, the following scenario. A large enough object would collapse classically until an event…

New physics scenarios beyond the Standard Model predict the existence of milli-charged particles. So far, only spin-1/2 and spin-0 milli-charged particles have been considered in literature, leaving out the interesting case of spin-1. We…

We suggest that dark matter is made up of massive quark objects that have survived from the Big Bang, representing the ground state of ``baryonic'' matter. Hence, there was no overall phase transition of the original quark matter, but only…

Some new challenges for an experiment and observation, which are consequences of the model of low-energy quantum gravity by the author, are considered here. In particular, the property of asymptotic freedom of this model leads to the…

Short gamma ray bursts are presumably results of binary neutron star mergers, which lead to the formation of a stellar mass black hole, surrounded by a remnant matter. The strong magnetic fields help collimate jets of plasma, launched along…

Black holes are extreme outcomes of General Relativity, and can form through a variety of ways, including gravitational collapse of massive stars, or quantum fluctuations in the early universe. Here, we ask the question of whether they can…

Gamma ray bursts (GRBs) are short and intense pulses of $\gamma$-rays arriving from random directions in the sky. Several years ago Amelino-Camelia et al. pointed out that a comparison of time of arrival of photons at different energies…

Short gamma-ray bursts (sGRBs) show a large diversity in their properties. This suggests that the observed phenomenon can be caused by different "central engines" or that the engine produces a variety of outcomes depending on its…

We systematically study the shortest time duration gamma ray bursts and find unique features that are best interpreted as sources of a galactic origin. There is a significant angular asymmetry and the V/Vmax distribution provides evidence…

The present surge for the astrophysical relevance of boson stars stems from the speculative possibility that these compact objects could provide a considerable fraction of the non-baryonic part of dark matter within the halo of galaxies.…

Robust generation of gamma-ray bursts (GRBs) implies the formation of outflows with very low baryon loads and highly relativistic velocities, but more baryon-rich, slower outflows are also likely to occur in most GRB central engine…

It has been revealed using microlensing that a considerable part, possibly more than half, of the dark matter in the halo of our Galaxy consists of objects with a mass spectrum ranging from 0.05 to 0.8 of the solar mass. What is the nature…

The last five years have seen growing challenges to the traditional paradigm of a core collapse supernova powered by the neutrino emission of a young proto-neutron star. Chief among these challenges are gamma-ray bursts (GRBs) and the…

If the preon structure of quarks, leptons and gauge bosons will be proved then in the Universe during relativistic phase transition the production of nonperturbative preon condensates has been occured collective excitations of which are…

We construct gravitational atoms including self-gravity, obtaining solutions of the Einstein-Klein-Gordon equations for a scalar field surrounding a non-rotating black hole in a quasi-stationary approximation. We resolve the region near the…

It is generally believed that long-duration gamma-ray bursts (GRBs) are associated with massive star core-collapse, whereas short-duration GRBs are associated with mergers of compact star binaries. However, growing observations have…