Related papers: Star Models with Dark Energy
A two-component fluid representing dark energy is studied. One of the components has a polytropic form, while the other has a barotropic form. Exact solutions are obtained and the cosmological parameters are constrained using supernova type…
Dark energy models and modified gravity theories have been actively studied and the behaviors in the solar system have been also carefully investigated in a part of the models. However, the isotropic solutions of the field equations in the…
In the standard model of cosmology, dark matter and dark energy are presently the two main contributors to the total energy in the Universe. However, these two dark components are still of unknown nature, and many alternative explanations…
A nearly black, gravitationally intense star of semi-transparent, spherical, massive shell containing a few pointlike light sources inside would be perceived not like a three-dimensional ball for a localized observer outside the shell in…
This is a second paper of a series of two. In this paper, we directly correct the problem pointed out in the first paper of this series, dark energy does not cluster on the scale of galaxy clusters, but the current describing the flowing of…
In this work, we derive rigorous and universal bounds on the geometric characteristics of black holes in asymptotically flat spacetimes under assumptions that weak energy condition is satisfied. We prove that the event horizon radius, the…
We consider a gravastar model made of anisotropic dark energy with an infinitely thin spherical shell of a perfect fluid with the equation of state $p = (1-\gamma)\sigma$ with an external de Sitter-Schwarzschild region. It is found that in…
The concept of dark energy can be used as a possible option to prevent the gravitational collapse of compact objects into singularities. It affects the universe on the largest scale, as it is responsible for our universe's accelerated…
The black hole model with a self-gravitating charged spherical symmetric dust thin shell as a source is considered. The Schroedinger-type equation for such a model is derived. This equation appeared to be a finite differences equation. A…
Dark Stars are stellar objects made (almost entirely) of hydrogen and helium, but powered by the heat from Dark Matter annihilation, rather than by fusion. They are in hydrostatic and thermal equilibrium, but with an unusual power source.…
Observations show that the expansion of the Universe is accelerating. This requires that the dominant constituent of matter in the Universe has some unusual properties like negative pressure. This exotic component has been given the name…
Recently, we have shown that dynamically stable ergostar solutions (equilibrium neutron stars that contain an ergoregion) with a compressible and causal equation of state exist [A. Tsokaros, M. Ruiz, L. Sun, S. L. Shapiro, and K. Ury\=u,…
This paper is an investigation of the stability of some ideal stars. It is in- tended as a study in General Relativity, with emphasis on the coupling to matter, eventually aimed at a better understanding of very strong gravitational fields…
A fully self-consistent model of the neutron star inner crust based upon models of the nucleonic equation of state at zero temperature is constructed. The results nearly match those of previous calculations of the inner crust given the same…
Despite the great progress of current cosmological measurements, the nature of the dominant component of the universe, coined dark energy, is still an open question. Early Dark Energy is a possible candidate which may also alleviate some…
We present a spherically symmetric solution of the general relativistic field equations in isotropic coordinates for charged fluid with pressure anisotropy, compatible with a super dense star modeling. Further, we have constructed an…
A new class of models of stellar discs is introduced and used to build a self-consistent model of our Galaxy. The model is defined by the parameters that specify the action-based distribution functions (DFs) f(J) of four stellar discs…
We study the generalization of the mass function of classes of regular spherically symmetric black holes solutions of in $ 4D $ coming from the coupling of General Relativity with Non-linear Electrodynamics, through the requirement of the…
Starlight in the Universe impedes the passage of high energy (e.g. TeV) gamma rays due to positron-electron pair production. The history of this stellar radiation field depends upon observations of star formation rate which themselves can…
Mounting observational data confirm that about 73% of the energy density consists of dark energy which is responsible for the current accelerated expansion of the Universe. We present observational evidences and dark energy projects. We…