Related papers: Dark energy stars: Stable configurations
Dark energy stars are finite size astrophysical objects with an interior equation of state typical of dark energy. Examples are self-gravitating false vacuum bubbles, vacuum non-singular black holes, and gravastars. We present a…
The dynamical properties of spherically symmetric galaxy models, where a Jaffe (1983) stellar density profile is embedded in a total mass density decreasing as $r^{-3}$ at large radii, are presented. The orbital structure of the stellar…
We present a comprehensive study of compact stars admixed with non-self annihilating self-interacting fermionic dark matter, delineating the dependence on the nuclear equation of state by considering the two limiting parametrized equations…
We investigate the stability of stars with a density discontinuity between a high-density core and a very low density mantle. Previous work on "strange dwarfs" suggested that such a discontinuity could stabilize stars that would have been…
Astrophysical compact stars provide a natural laboratory for testing theoretical models which are otherwise difficult to prove from an experimental setup. In our present work we analyse an exact solution to the Einstein-Maxwell system for a…
We discuss a new method which is potentially capable of constraining cosmological parameters using observations of giant luminous arcs in rich X-ray clusters of galaxies. The mass profile and the mass normalization of the lenses are…
A physically realistic stellar model with a simple expression for the energy density and conformally flat interior is found. The relations between the different physical conditions are used without graphic proofs. It may represnet a real…
A class of solutions of Einstein field equations satisfying Karmarkar embedding condition is presented which could describe static, spherical fluid configurations, and could serve as models for compact stars. The fluid under consideration…
We parameterize the core of compact spherical star configurations by a mass ($m_x$) and a radius ($r_x$) and study the resulting admissible areas in the total-mass vs. total-radius plane. The employed fiducial equation-of-state models of…
We investigate a compact spherically symmetric relativistic body with anisotropic particle pressure profiles. The distribution possesses characteristics relevant to modeling compact stars within the framework of general relativity. For this…
In this paper we found a new model for compact star with anisotropic matter distribution considering the new version of Chaplygin fluid equation of state of Errehymy and Daoud (2021). We specify the particular form of the metric potential…
We present the radial distribution of the dark matter in two massive, X-ray luminous galaxy clusters, Abell~2142 and Abell~2319, and compare it with the quantity predicted as apparent manifestation of the baryonic mass in the context of the…
In this article, an exact solution of Einstein's field equations for spherically symmetric anisotropic matter distributions in isotropic coordinates is obtained. For this, the solution has been obtained by using a generalized physically…
We study gravitationally bound, spherically symmetric equilibrium configurations consisting of ordinary (neutron-star) matter and of a phantom/ghost scalar field which provides the nontrivial topology in the system. For such mixed…
We study a class of analytic models for a dark matter halo surrounding a Schwarzschild black hole sitting at the center of a galaxy, with a variable inner radius $r_{\text{in}}$ at which the density profile of the dark matter halo vanishes.…
The inner regions of the most massive compact stellar objects might be occupied by a phase of quarks. Since the observations of the massive pulsars PSR J1614-2230 and of PSR J0348+0432 with about two solar masses, the equations of state…
In this study, we present a generalized spherically symmetric, anisotropic and static compact stellar model in $f(T)$ gravity, where $T$ represents the torsion scalar. By employing the Karmarkar condition we have obtained embedding class 1…
Dynamical properties of spherically symmetric galaxy models where both the stellar and total mass density distributions are described by the Jaffe (1983) profile (with different scale-lenghts and masses), are presented. The orbital…
We investigate whether compact stars having Tolman-like interior geometry admit conformal symmetry. Taking anisotropic pressure along the two principal directions within the compact object, we obtain physically relevant quantities such as…
We generalize the small scale dynamics of the universe by taking into account models with an equation of state which evolves with time, and provide a complete formulation of the cluster virialization attempting to address the nonlinear…