Related papers: Likely formation of general relativistic radiation…
In course of the consolidation of nucleon (neutron) spacing inside a compact star, two key factors are expected to come into play side by side: the lack of self-stabilization against shutting into black hole (BH) and forthcoming phase…
We investigate whether a dark matter with substantial amounts of pressure, comparable in magnitude to the energy density, could be a viable candidate for the constituent of dark matter halos. We find that galaxy halos models, consistent…
The high-redshift star formation rate (SFR) is difficult to measure directly even by modern approaches. Long-duration gamma-ray bursts (GRBs) can be detected to the edge of the visible universe because of their high luminorsities. The…
We investigate the collapse of a circularly symmetric star with outgoing radiation in ($2+1$)-dimensional anti-de Sitter spacetime. The exterior spacetime of the collapsing star is assumed to be described by the non-static generalization of…
The crucial role played by pressure in general relativity is explored in the mathematically simple context of a static spherically symmetric geometry. By keeping all pressure terms, the standard formalisms of rotation curve and…
New data imply that the average velocity of radio pulsars is large \cite{hla93}. Under the assumption that these data imply that a pulsar is born with an ``intrinsic'' kick, we investigate whether such kicks can be a consequence of…
We perform a careful investigation of the problem of physically realistic gravitational collapse of massive stars in f(R)-gravity. We show that the extra matching conditions that arise in the modified gravity imposes strong constraints on…
A theoretical study of some electrodynamic features of a region close to a {\it slowly-rotating} magnetized relativistic star is performed. To be a little more specific, based on the solution-generating method given by Wald, the magnetic…
We examine spherical gravitational collapse of a matter model with vanishing radial pressure and non-zero tangential pressure. It is seen analytically that the collapsing cloud either forms a black hole or disperses depending on values of…
We study relativistic stars in the context of scalar tensor theories of gravity that try to account for the observed cosmic acceleration and satisfy the local gravity constraints via the chameleon mechanism. More specifically, we consider…
We present theoretical predictions for the spectral, temporal and intensity signatures of the electromagnetic radiation emitted during the process of the gravitational collapse of a stellar core to a black hole, during which electromagnetic…
The collapse of supermassive stars (SMSs) via the general-relativistic (GR) instability would provide a natural explanation to the existence of the most extreme quasars. The presence of dark matter in SMSs is thought to potentially impact…
We use three-dimensional radiation hydrodynamic (RHD) simulations to study the formation of massive star clusters under the combined effects of direct ultraviolet (UV) and dust-reprocessed infrared (IR) radiation pressure. We explore a…
High resolution X-ray spectra reveal hidden cooling flows depositing cold gas at the centres of massive nearby early-type galaxies with little sign of normal star formation. Optical observations are revealing that a bottom-heavy Initial…
In this paper we compute general-relativistic polytropic models simulating rigidly rotating, pulsating neutron stars. These relativistic compact objects, with a radius of $\sim 10 \, \mathrm{km}$ and mass between $\sim 1.4$ and $3.2$ solar…
We study the dynamical evolution of a phase-transition-induced collapse neutron star to a hybrid star, which consists of a mixture of hadronic matter and strange quark matter. The collapse is triggered by a sudden change of equation of…
Several classes of conformally-flat and spherically symmetric exact solutions to the Einstein field equations coupled with either a massless scalar field or a radiation fluid are given, and their main properties are studied. It is found…
Probing gravity in its strongest regime is a central goal of modern physics, as the nature of the most compact objects reflects fundamental aspects of Einstein's theory of general relativity (GR). In GR, black holes are regarded as the most…
There is a lot of current interest in sources of gravitational waves and active ongoing projects to detect such radiation, such as the LIGO project. These are long wavelength, low frequency gravitational waves. LISA would be sensitive to…
We present a model of star formation in self-gravitating turbulent gas. We treat the turbulent velocity $v_T$ as a dynamical variable, and assume that it is adiabatically heated by the collapse. The theory predicts the run of density,…