Narrow Results

In this work, gravitational collapse has been studied for quasi-spherical spacetime with dust or anisotropic pressure as the matter content. A linear transformation on the initial data set and of the area radius shows the invariance of the physical parameters as well as the final fate of collapse, considering an arbitrary function of r as the initial area radius.

We study quasi-spherical Szekeres space–time (which possess no killing vectors) for perfect fluid, matter with tangential stress only and matter with anisotropic pressure respectively. In the first two cases cosmological solutions have been obtained and their asymptotic behavior have been examined while for anisotropic pressure, gravitational collapse has been studied and the role of the pressure has been discussed.

A detailed study of higher-dimensional quasi-spherical gravitational collapse with radial and tangential stresses has been done and the role of initial data, anisotropy and inhomogeneity has been investigated in determining the end state of collapse. By linear scaling the initial data set and the area radius, it is found that the dynamics of quasi-spherical collapse remains invariant. In other words, the linear transformation identifies an equivalence class of data sets for which physical parameters like density, pressures (radial and tangential), shear remain invariant and the final state of collapse is identical (black hole or naked singularity). Finally, the role of anisotropy and inhomogeneity has been studied by proving some propositions.

We study gravitational collapse in higher dimensional quasi-spherical Szekeres space–time for matter with anisotropic pressure. Both local and global visibility of central curvature singularity has been studied and it is found that with proper choice of initial data it is possible to show the validity of Cosmic Censorship Conjecture for six and higher dimensions. Also the role of pressure in the collapsing process has been discussed.

Collapsing process is studied in special type of inhomogeneous spherically symmetric space-time model (known as IFRW model), having no time-like Killing vector field. The matter field for collapse dynamics is considered to be perfect fluid with anisotropic pressure. The main issue of this investigation is to examine whether the end state of the collapse to be a naked singularity or a black hole. Finally, null geodesics is studied near the singularity.