Related papers: How clustering dark energy affects matter perturba…
Dark matter, the major component of the matter content of the Universe, played a significant role at early stages during structure formation. But at present the Universe is dark energy dominated as well as accelerating. Here, the presence…
We study the concentration parameters, their mass dependence and redshift evolution, of dark-matter halos in different dark-energy cosmologies with constant and time-variable equation of state, and compare them with "standard'' Lambda-CDM…
In this work we consider the impact of spatially-uniform but time-varying dark energy (or `dynamical dark energy', DDE) on large-scale structure in a spatially flat universe, using large cosmological hydrodynamical simulations that form…
Two methods of constraining the properties of dark energy are weak lensing tomography and cluster counting. Uncertainties in mass calibration of clusters can be reduced by using the properties of halo clustering (the clustering of…
In this paper the cosmological evolution of a holographic dark energy model with a non-linear interaction between the dark energy and dark matter components in a FRW type flat universe is analysed. In this context, the deceleration…
Thus far, there does not appear to be an agreed (or adequate) definition of homogeneous dark energy (DE). This paper seeks to define a valid, adequate homogeneity condition for DE. Firstly, it is shown that as long as $w_x \neq -1$, DE must…
The fact that the energy densities of dark energy and matter are similar currently, known as the coincidence problem, is one of the main unsolved problems of cosmology. We present here a model in which a spatial curvature of the universe…
The acceleration of the expansion of the universe, ascribed to a dark energy, is one of the most intriguing discoveries in science. In addition to precise, systematics controlled data, clear, robust interpretation of the observations is…
We investigate and quantify the impact of mixed (cold and warm) dark matter models on large-scale structure observables. In this scenario, dark matter comes in two phases, a cold one (CDM) and a warm one (WDM): the presence of the latter…
We investigate observational constraints on the curvature of the universe not restricting ourselves to a cosmological constant as dark energy, in particular allowing a dark energy equation of state to evolve with time in several ways. We…
As is known above 90% of the energy content in Universe is made of unknown dark component. Usually this dark fluid is separated into two parts: dark matter and dark energy. However, it may be a mixture of these two energy components, or…
We explore the properties of dark energy models for which the equation-of-state, w, defined as the ratio of pressure to energy density, crosses the cosmological-constant boundary w = -1. We adopt an empirical approach, treating the dark…
We explore the fate of the universe given the possibility that the density associated with `dark energy' may decay slowly with time. Decaying dark energy is modeled by a homogeneous scalar field which couples minimally to gravity and whose…
We study the dynamical properties and space distribution of dark energy in the weak and strong gravitational fields caused by inhomogeneities of matter in the static world of galaxies and clusters. We show that the dark energy in the weak…
We examine cyclic phantom models for the universe, in which the universe is dominated sequentially by radiation, matter, and a phantom dark energy field, followed by a standard inflationary phase. Since this cycle repeats endlessly, the…
A hypothetical dark energy component may have an equation of state that is different from a cosmological constant and possibly even changing in time. The spacing of the cosmic microwave background peaks is sensitive to the ratio of the…
Black holes, dark energy, and the Higgs field are all currently established, exciting, and mysterious, each in its own way. Cosmological data show that dark energy may evolve with time. The electroweak phase transition during stellar…
We reconstruct the effective Equation of State (EoS) within the framework of General Relativity (GR) theory in a homogeneous and isotropic FLRW Universe, which is assumed to be composed of matter and Dark Energy (DE). Our analysis employs a…
We assume the cosmological dark sector to consist of pressureless matter and holographic dark energy with a cutoff length proportional to the Ricci scale. The requirement of separate energy-momentum conservation of the components is shown…
(abridged) We used a suite of numerical cosmological simulations in order to investigate the effect of gas cooling and star formation on the large scale matter distribution. The simulations follow the formation of cosmic structures in five…