Saibal Ray

Dark Energy Models with Variable Equation of State Parameter

The dark energy models with variable equation of state parameter ω are investigated by using law of variation of Hubble’s parameter that yields the constant value of deceleration parameter. Here the equation of state parameter ω is found to be time dependent and its existing range for this model is consistent with the recent observations of SN Ia data, SN Ia data (with CMBR anisotropy) and galaxy clustering statistics. The physical significance of the dark energy models have also been discussed.

Strange stars in Krori-Barua space-time

The singularity free space-time metric obtained by Krori and Barua (J. Phys. A, Math. Gen. 8:508, 1975) satisfies the physical requirements of a realistic star. Consequently, we explore the possibility of applying the Krori and Barua model to describe ultra-compact objects like strange stars. For it to become a viable model for strange stars, bounds on the model parameters have been obtained. Consequences of a mathematical description to model strange stars have been analyzed.

Anisotropic strange star with de Sitter spacetime

Stars can be treated as self-gravitating fluid. Krori and Barua (J. Phys. A., Math. Gen. 8:508, 1975) gave an analytical solution to that kind of fluids. In this connection, we propose a de Sitter model for an anisotropic strange star with the Krori–Barua spacetime. We incorporate the existence of the cosmological constant on a small scale to study the structure of anisotropic strange stars and come to the conclusion that this doping is very well compatible with the well-known physical features of strange stars.

The dark energy equation of state

We perform a study of cosmic evolution with an equation of state parameter

Singularity-free dark energy star

\omega(t)=\omega_0+\omega_1(t\dot H/H)

ANISOTROPIC COMPACT STARS WITH VARIABLE COSMOLOGICAL CONSTANT

by selecting a phenomenological

Charged gravastars admitting conformal motion

\Lambda

A comparison of Hořava–Lifshitz gravity and Einstein gravity through thin-shell wormhole construction

model of the form,

Searching for higher-dimensional wormholes with noncommutative geometry

\dot\Lambda\sim H^3

Thin-shell wormholes from charged black holes in generalized dilaton-axion gravity

. This simple proposition explains both linearly expanding and inflationary Universes with a single set of equations. We notice that the inflation leads to a scaling in the equation of state parameter,