2006 (IPP)
Permanent URI for this collectionhttp://localhost:4000/handle/11007/335
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Item Exact non-spherical radiating collapse(2006-07-30) Ghosh, S. G.; Deshkar, D. W.We study the junction conditions for non-spherical collapsing radiating star consisting of a shearing fluid undergoing radial heat flow with outgoing radiation. Radiation of the system is described by plane symmetric version of Vaidya solution. Junction conditions which match the collapse solutions to an exterior Vaidya metric show that, at the boundary, the pressure is proportional to the magnitude of the heat flow vector. Physical quantities, analogous to spherical symmetry related to the local conservation of momentum and surface red-shift, are also obtained. Finally, exact gravitational collapse solutions, for both shear and shear-free case, have been obtained by integrating a field equation.Item Five dimensional dust collaspe with cosmological constant(2006-07-31) Ghosh, S. G.; Deshkar, D. W.; Saste, N. N.We study five dimensional spherical collapse of a inhomogeneous dust in presence of a positive cosmological constant. The general interior solutions, in the closed form, of the Einstein field equations, i.e., the 5D Tolman-Bondi-de Sitter, is obtained which in turn is matched to exterior 5D Scwarschild-de Sitter. It turns out that the collapse proceed in the same way as in the Minkowski background, i.e., the strong curvature naked singularities form and thus violate the cosmic censorship conjecture. A brief discussion on the causal structure singularities and horizons is also given.