Related papers: Exact dark energy star solutions

Einstein field equations for anisotropic spheres are solved and exact interior solutions obtained. This paper extends earlier treatments to include anisotropic models which accommodate a wider variety of physically viable energy densities.…

The dynamical analysis for coupled dark energy with dark matter is presented, where a complex scalar field is taken into account and it is considered in the presence of a barothropic fluid. We consider three dark energy candidates:…

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 exact tunneling solutions in scalar field theory for potential barriers composed of linear or quadratic patches. We analytically continue our solutions to imaginary Euclidean radius in order to study the profile of the scalar field…

The book elucidates the current state of the dark energy problem and presents the results of the authors, who work in this area. It describes the observational evidence for the existence of dark energy, the methods and results of…

We have proposed a new model of dark energy star consisting of five zones namely, solid core of constant energy density, the thin shell between core and interior, an inhomogeneous interior region with anisotropic pressures, thin shell and…

A general class of cosmological models driven by a nonlocal scalar field inspired by the string field theory is studied. Using the fact that the considering linear nonlocal model is equivalent to an infinite number of local models we have…

The amount and nature of dark energy (DE) can be tightly constrained by measuring the spatial correlation features and evolution of a sample of ~ 100,000 galaxy clusters over the redshift range 0<z < 1.5. Such an X-ray survey will discover…

The today estimated value of dark energy can be achieved by the vacuum condensate induced by neutrino mixing phenomenon. Such a tiny value is recovered for a cut-off of the order of Planck scale and it is linked to the sub eV neutrino mass…

We identify troubling cases of so-called `permanent underdetermination' in both dark energy and inflationary cosmology. We bring to bear (a) a taxonomy of possible responses to underdetermination, and (b) an understanding of both dark…

The standard model of cosmology suggests the existence of two components, "dark matter" and "dark energy", which determine the fate of the Universe. Their nature is still under investigation, and no direct proof of their existences has…

Velocity-dependent interactions in a fundamental-string dominated universe lead quite naturally, with reasonable assumptions on initial conditions, to an accelerating expanding universe without assuming the existence of a cosmological…

The interest in studying relativistic compact objects play an important role in modern astrophysics with an aim to understand several astrophysical issues. It is therefore natural to ask for internal structure and physical properties of…

A successor to the standard hot big-bang cosmology is emerging. It greatly extends the highly successful hot big-bang model. A key element of the New Standard Cosmology is dark energy, the causative agent for accelerated expansion. Dark…

The most studied way to explain the current accelerated expansion of the universe is to assume the existence of dark energy; a new component that fill the universe, does not clumps, currently dominates the evolution, and has a negative…

The warm dark matter (WDM) can be described by simple and useful model called reduced relativistic gas (RRG). In this work, it is analytically constructed the scalar field actions minimally and non-minimally coupled to gravity, which are…

We investigate the late-time evolution of the Universe within a cosmological model in which dark matter and dark energy are identified with two interacting scalar fields. Using methods of qualitative analysis of dynamical systems, we…

We review a dynamical dark energy model scarcely studied in the literature and we introduce two possible generalizations. We discuss separately the behavior of the original model and a minimal extension of it by exploring some early and…

The physical process leading to the acceleration of the expansion of the universe is unknown. It may involve new high energy physics or extensions to gravitation. Calling this generically dark energy, we examine the consistencies and…

We find exact solutions leading to power law accelerated expansion for a homogeneous, isotropic and spatially flat universe, dominated by an interacting mixture of cold dark matter and a tachyonic field such that the ratio of the energy…