We consider the late-time evolution of gravitational and electromagnetic perturbations in realistic rotating Kerr spacetimes. We give a detailed analysis of the mode-coupling phenomena in rotating gravitational collapse. A consequence of this phenomena is that the late-time tail is dominated by modes which, in general, may have an angular distribution different from the original one. In additio...

A class of perfect fluid collapse models is constructed to examine the final fate of a continual gravitational collapse. While the pressure could be negative in the interior of the cloud, the weak-energy condition is satisfied. The collapsing star radiates away its matter as the process of gravitational collapse evolves, so as to avoid the formation of trapped surfaces. The collapsing interior ...

We investigate here the gravitational collapse end states for a spherically symmetric perfect fluid with an equation of state p = kρ. It is shown that given a regular initial data in terms of the density and pressure profiles at the initial epoch from which the collapse develops, the black hole or naked singularity outcomes depend on the choice of rest of the free functions available, such as t...

We study gravitational collapse of the axion/dilaton eld in classical low energy string theory, at the threshold for black hole formation. A new critical solution is derived that is spherically symmetric and continuously self-similar. The universal scaling and echoing behavior discovered by Choptuik in gravitational collapse appear in a somewhat di erent form. In particular, echoing takes the f...

Abstract We construct an approximate solution which describes the gravitational emission from a naked singularity formed by the gravitational collapse of a cylindrical thick shell composed of dust. The assumed situation is that the collapsing speed of the dust is very large. In this situation, the metric variables are obtained approximately by a kind of linear perturbation analysis in the backg...

A distinguishable physical property between a naked singularity and a black-hole, formed during a gravitational collapse has important implications for both experimental and theoretical relativity. We examine the energy radiated during the spherically symmetric Gravitational collapse in this context within the framework of general relativity. It is shown that total energy radiated( Mass Loss) d...

We present here a simple model of radiative gravitational collapse with radial heat flux which describes qualitatively the stages close to the formation of a superdense cold star. Starting with a static general solution for a cold star, the model can generate solutions for the earlier evolutionary stages. The temporal evolution of the model is specified by solving the junction conditions approp...

X iv :g rqc /0 30 80 37 v1 1 2 A ug 2 00 3 Role of Initial Data in Higher Dimensional Quasi-Spherical Gravitational Collapse Ujjal Debnath and Subenoy Chakraborty Department of Mathematics, Jadavpur University, Calcutta-32, India. (Dated: February 7, 2008) We study the gravitational collapse in (n+2)-D quasi-spherical Szekeres space-time (which possess no killing vectors) with dust as the matte...

We establish the formalism in the nonsymmetric gravitational theory (NGT) for stellar equilibrium and gravitational collapse. We study the collapse of a pressureless, spherically symmetric dust cloud. By assuming that the interior solution is smoothly matched at the surface of the star to the quasi-static, spherically symmetric vacuum solution, we find that the star does not collapse to a black...

We study the gravitational wave emission from the first stars which are assumed to be Very Massive Objects (VMOs). We take into account various feedback (both radiative and stellar) effects regulating the collapse of objects in the early universe and thus derive the VMO initial mass function and formation rate. If the final fate of VMOs is to collapse, leaving very massive black hole remnants, ...