Star models with dark energy

Abstract

We have constructed star models consisting of four parts: (i) a homogeneous inner core with anisotropic pressure (ii) an infinitesimal thin shell separating the core and the envelope; (iii) an envelope of inhomogeneous density and isotropic pressure; (iv) an infinitesimal thin shell matching the envelope boundary and the exterior Schwarzschild spacetime. We have analyzed all the energy conditions for the core, envelope and the two thin shells. We have found that, in order to have static solutions, at least one of the regions must be constituted by dark energy. The results show that there is no physical reason to have a superior limit for the mass of these objects but for the ratio of mass and radius.

Charged gravastars in higher dimensions

“…The above EOS is known in the literature as a 'false vacuum', 'degenerate vacuum', or 'ρ-vacuum' [19,20,21,22] which represents a repulsive pressure, an agent responsible for the accelerating phase of the Universe, and is termed as the Λ-dark energy [23,24,25,26,27]. It is argued by [16] that a charged gravastar seems to be connected to the dark star [28,29,30].…”

The dark energy star and stability analysis

“…An anisotropic dark energy star has been discussed in [2]. A star model with dark energy has been proposed in [3]. In this paper the authors have proposed a model of the dark energy star consisting of four regions and by analyzing the model they conclude that for a static solution at least one of the regions must be constituted by dark energy.…”

Singularity-free dark energy star

“…In the past, various model specific dark energy stars have been proposed (see for example, Ref. [4][5][6][7][8][9] and Ref. [10] for a recent review).…”