It is generally believed that the following is true: the classical gravitational field of a sufficiently massive star will overcome its neutron degeneracy pressure and, barring quantum gravitational effects in the final stages of collapse, the star will form a singularity of space-time. The initial conditions determine the precise nature of the singularity of the collapse: either the singularit...

We apply the recent results in Loop Quantum Cosmology and in the resolution of Black Hole singularity to the gravitational collapse of a star. We study the dynamic of the space time in the interior of the Schwarzschild radius. In particular in our simple model we obtain the evolution of the matter inside the star and of the gravity outside the region where the matter is present. The boundary co...

We simulate fragmentation and gravitational collapse of cold, magnetized molecular clouds. We explore the nonlinear development of an instability mediated by ambipolar diffusion, in which the collapse rate is intermediate to fast gravitational collapse and slow quasistatic collapse. Initially uniform stable clouds fragment into elongated clumps with masses largely determined by the cloud temper...

A core–collapse supernova might produce large amplitude gravitational waves if, through the collapse process, the inner core can aquire enough rotational energy to become dynamically unstable. In this report I present the results of 3-D numerical simulations of core collapse supernovae. These simulations indicate that for some initial conditions the post–collapse inner core is indeed unstable. ...

In this paper, we derive the general formulation by considering two arbitrary plane symmetric spacetimes using Israel’s method. As an example, we apply this formulation to known plane symmetric spacetimes. We take the Taub’s static metric in the interior region whereas Kasner’s non-static metric in the exterior region. It is shown that the plane collapses in some cases whereas it expands in som...

In this paper, we discuss gravitational collapse of spherically symmetric spacetimes. We derive a general formalism by taking two arbitrary spherically symmetric spacetimes with g00 = 1. Israel’s junction conditions are used to develop this formalism. The formulae for extrinsic curvature tensor are obtained. The general form of the surface energy-momentum tensor depending on extrinsic curvature...

The nature of gravitational collapse was the subject of debate and controversy for much of the last century. During the 1960’s and 1970’s our understanding of general relativity consolidated and culminated in our modern understanding of black holes and spacetime singularities. Since then, there has been significant advances in understanding the dynamics of gravitational collapse and the nature ...