Related papers: Virialization in Dark Energy Cosmology
Considering an arbitrary, varying equation of the state parameter, the thermodynamic properties of the dark energy fluid in a semiclassical loop quantum cosmology scenario, which we consider the inverse volume modification, is studied. The…
We study a cosmological implication of holographic dark energy in the Brans-Dicke gravity. We employ the holographic model of dark energy to obtain the equation of state for the holographic energy density in non-flat (closed) universe…
We consider the space-time associated with the evaporation of a black hole by quantum mechanical tunnelling events. It is shown that the surface through which tunnelling occurs is distinct from the global event horizon, and that this has…
In this paper we study the cosmological evolution of the holographic dark energy in a cyclic universe, generalizing the model of holographic dark energy proposed by Li. The holographic dark energy with $c<1$ can realize a quintom behavior;…
The aim of this paper is to answer the following two questions: (1) Given cosmological observations of the expansion history and linear perturbations in a range of redshifts and scales as precise as is required, which of the properties of…
The lately proposed vacuum matter coupling model (arXiv:1303.6568) seems to be able to provide solutions to a variety of problems in cosmology. This coupling expressed by a transition term between vacuum energy and matter, but we point out…
A non-trivial spatial topology of the Universe is a potentially observable attribute, which can be probed through the circles-in-the-sky for all locally homogeneous and isotropic universes with no assumptions on the cosmological parameters.…
An isotropic and homogeneous cosmological model with a source of dark energy is studied. That source is simulated with a viscous relativistic fluid with minimal causal correction. In this model the restrictions on the parameters coming from…
We aim at the construction of dark energy models without exotic matter but with a phantom-like equation of state (an effective phantom phase). The first model we consider is decaying vacuum cosmology where the fluctuations of the vacuum are…
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…
A huge amount of good quality astrophysical data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision…
Holographic dark energy with the Hubble radius as infrared cutoff has been considered as a candidate to explain the late-time cosmic acceleration and it can solve the coincidence problem. In this scenario, a non-zero equation of state is…
The coincidence problems and other dynamical features of dark energy are studied in cosmological models with variable cosmological parameters and in models with the composite dark energy. It is found that many of the problems usually…
The coupling between the dark components provides a new approach to mitigate the coincidence problem of cosmological standard model. In this paper, dark energy is treated as a fluid with a constant equation of state, whose coupling with…
The present paper deals with the gravitational collapse of an inhomogeneous spherical star consisting of dust fluid in the background of dark energy components with linear equation of state. We discussed the development of apparent horizon…
In this paper we review in detail a number of approaches that have been adopted to try and explain the remarkable observation of our accelerating Universe. In particular we discuss the arguments for and recent progress made towards…
In this work, gravitational collapse of a spherical cloud, consists of both dark matter and dark energy in the form of modified Chaplygin gas is studied. It is found that dark energy alone in the form of modified Chaplygin gas forms black…
An overview is presented of a recently proposed "radically conservative" solution to the problem of dark energy in cosmology. The proposal yields a model universe which appears to be quantitatively viable, in terms of its fit to supernovae…
We discuss the consequences of possible sign changes of the $Q$-function which measures the energy transference between dark energy and dark matter. We investigate this scenario from a holographic perspective to modeling the dark energy by…
We propose a new UV-complete dark energy model which is \underbar{\it neither} a cosmological constant nor a slowly rolling scalar field. Our dark energy is the flux of a top form in a hidden sector gauge theory similar to QCD. The top form…