Related papers: Inhomogeneous Dark Energy
The non-linearity of Einstein's equations makes it possible for small-scale matter inhomogeneities to affect the Universe at cosmological distances. We study the size of such effects using a simple heuristic model that captures the most…
In the $\Lambda$CDM model, dark energy is viewed as a constant vacuum energy density, the cosmological constant in the Einstein--Hilbert action. This assumption can be relaxed in various models that introduce a dynamical dark energy. In…
As indicated by Einstein's general relativity, matter and geometry are two faces of a single nature. In our point of view, extra dimensions, as a member of the {\em geometry face}, will be treated as a part of the {\em matter face} when…
The integrated Sachs-Wolfe (ISW) effect in the cosmic microwave background (CMB) as measured through its correlation with galaxies provides a unique opportunity to study the dynamics of the dark energy through its large scale clustering…
The observed dark energy in the universe might give particles inertial mass. We investigate one realization of this idea, that the dark energy field might be a decayed scalar component of a supermultiplet field in the early universe that…
We consider a model where both dark energy and dark matter originate from the coupling of a scalar field with a non-conventional kinetic term to, both, a metric measure and a non-metric measure. An interacting dark energy/dark matter…
We propose a dark energy density based on the Gauss-Bonnet 4-dimensional invariant and its modification. This model avoids the necessity of introducing the black hole limit to define the holographic density, since it can be considered as a…
One of the biggest mysteries in cosmology is Dark Energy, which is required to explain the accelerated expansion of the universe within the standard model. But maybe one can explain the observations without introducing new physics, by…
The presence of dark energy in the Universe is inferred directly from the accelerated expansion of the Universe, and indirectly, from measurements of cosmic microwave background (CMB) anisotropy. Dark energy contributes about 2/3 of the…
We investigate the non-linear evolution of spherical density and velocity perturbations of dark matter and dark energy in the expanding Universe. For that we have used the conservation and Einstein equations to describe the evolution of…
It has been recently proposed that the presence of a temporal electromagnetic field on cosmological scales could explain the phase of accelerated expansion that the universe is currently undergoing. The field contributes as a cosmological…
By relaxing the conventional assumption of a purely gravitational interaction between dark energy and dark matter, substantial alterations to the growth of cosmological structure can occur. In this work we focus on the homogeneous transfer…
It is suggested that the apparently disparate cosmological phenomena attributed to so-called 'dark matter' and 'dark energy' arise from the same fundamental physical process: the emergence, from the quantum level, of spacetime itself. This…
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…
Cosmological dark energy is a natural source of variation of the fine structure constant. Using a model-independent approach we show that once general assumptions about the alpha-varying interactions are made, astronomical probes of its…
We present evidence that a special class of gravitationally-coupled hidden sectors, in which conformal invariance is dynamically broken in a controlled way, exhibit the properties of dark energy. Such quantum field theories may appear while…
The present standard model of cosmology states that the known particles carry only a tiny fraction of total mass and energy of the Universe. Rather, unknown dark matter and dark energy are the dominant contributions to the cosmic energy…
The interaction between the quantum vacuum and a weak gravitational field is calculated for the vacuum fields of quantum electrodynamics. The result shows that the vacuum state is modified by the gravitational field, giving rise to a…
Observational evidence of dark energy that makes the Universe nearly flat at the present epoch is very strong. We study the link between spatial continuity and dark energy. We assume that comoving space is a compact 3-manifold of constant…
Entangled states in the universe may change interpretation of observations and even revise the concept of dark energy.