arXiv subjects

Soma Nath

Publications and source records attributed to Soma Nath.

5 recordsLinked to original sources

arXiv2007

Junction Conditions and Consequences of Quasi-Spherical Space-Time with Electro-Magnetic Field and Vaidya Matric

In this work the junction conditions between the exterior Reissner-Nordstrom-Vaidya space-time with the interior quasi-spherical Szekeres space-time have been studied for analyzing gravitational collapse in the presence of a magneto-hydrodynamic fluid undergoing dissipation in the form of heat flow. We have discussed about the apparent horizon and have evaluated the time difference between the formation of apparent horizon and central singularity.

gr-qc↗

arXiv2006

Quasi-spherical collapse with cosmological constant

The junction conditions between static and non-static space-times are studied for analyzing gravitational collapse in the presence of a cosmological constant. We have discussed about the apparent horizon and their physical significance. We also show the effect of cosmological constant in the collapse and it has been shown that cosmological constant slows down the collapse of matter.

gr-qc↗

arXiv2005

Gravitational collapse due to dark matter and dark energy in the brane world scenario

Gravitational collapse of FRW brane world embedded in a conformaly flat bulk is considered for matter cloud consists of dark matter and dark energy with equation of state $p=ερ$ $(ε<-{1/3})$. The effect of dark matter and dark energy is being considered first separately and then a combination of them both with and without interaction. In some cases the collapse leads to black hole in some other cases naked singularity appears.

gr-qc↗

arXiv2004

Anisotropic Brane Cosmology with Variable $G$ and $Λ$

In this work, the cosmological implications of brane world scenario are investigated when the gravitational coupling $G$ and the cosmological term $Λ$ are not constant but rather there are time variation of them. From observational point of view, these time variations are taken in the form $\frac{\dot{G}}{G}\sim H$ and $Λ\sim H^{2}$. The behavior of scale factors and different kinematical parameters are investigated for different possible scenarios where the bulk cosmological constant $Λ_{5}$ can be zero, positive or negative.

gr-qc↗

arXiv2003

Non-adiabatic collapse of a quasi-spherical radiating star

A model is proposed of a collapsing quasi-spherical radiating star with matter content as shear-free isotropic fluid undergoing radial heat-flow with outgoing radiation. To describe the radiation of the system, we have considered both plane symmetric and spherical Vaidya solutions. Physical conditions and thermodynamical relations are studied using local conservation of momentum and surface red-shift. We have found that for existence of radiation on the boundary, pressure on the boundary is not necessary.

gr-qc↗