Related papers: Probing Dynamical Dark Energy with Press-Schechter…
The discovery ten years ago that the expansion of the Universe is accelerating put in place the present cosmological model, in which the Universe is composed of 4% baryons, 20% dark matter, and 76% dark energy. Yet the underlying cause of…
Below scales of about 100/h Mpc our universe displays a complex inhomogeneous structure dominated by voids, with clusters of galaxies in sheets and filaments. The coincidence that cosmic expansion appears to start accelerating at the epoch…
The luminosity distance-redshift relation is one of the fundamental tools of modern cosmology. We compute the luminosity distance-redshift relation in a perturbed flat matter-dominated Universe, taking into account the presence of…
We investigate unbound dark matter particles in halos by tracing particle trajectories in a simulation run to the far future (a = 100). We find that the traditional sum of kinetic and potential energies is a very poor predictor of which…
The discovery of dark energy by the first generation of high-redshift supernova surveys has generated enormous interest beyond cosmology and has dramatic implications for fundamental physics. Distance measurements using supernova explosions…
To determine the nature of dark energy from observational data, it is important that we use model-independent and optimal methods. We should probe dark energy using its density (allowed to be a free function of cosmic time) instead of its…
It is proposed that dark energy may become dominant over standard matter due to universe expansion (curvature decrease). Two models: non-linear gravity-matter system and modified gravity may provide the effective phantom or effective…
This paper presents an investigation of cosmological dynamics of tachyon fluid coupled to varyingmass dark matter particles in the background of spatially flat FLRW universe. The mechanism of varying mass particles scenario assumes the mass…
We propose the Locally Pumped Dark Energy (LPDE) mechanism in which cosmic acceleration is triggered by the emergence of non-linear dark matter structure. In an effective-field-theory description, coarse-graining over the density contrast…
The accelerated expansion of the universe is ascribed to the existence of dark energy. Black holes accretion of dark energy induces a mass change proportional to the energy density and pressure of the background dark energy fluid. The time…
There is compelling evidence that the Universe is undergoing a late phase of accelerated expansion. One of the simplest explanations for this behaviour is the presence of dark energy. A plethora of microphysical models for dark energy have…
Most of the models leading to a current state of cosmic accelerated expansion fail to address the coincidence problem, i.e., that the dark energy density and the energy density of the matter fluid are of the same order precisely today. We…
Quantum mechanics together with general relativity leads to the K\'arolyh\'azy relation and a corresponding energy density of quantum fluctuations of space-time. Based on the energy density we propose a dark energy model, in which the age…
All models of dynamical dark energy possess fluctuations, which affect the number of galaxy clusters in the Universe. We have studied the impact of dark energy clustering on the number of clusters using a generalization of the spherical…
Dynamical wave function collapse models entail the continuous liberation of a specified rate of energy arising from the interaction of a fluctuating scalar field with the matter wave function. We consider the wave function collapse process…
Dark energy and dark matter constitute 95% of the observable Universe. Yet the physical nature of these two phenomena remains a mystery. Einstein suggested a long-forgotten solution: gravitationally repulsive negative masses, which drive…
As an explanation for the acceleration of the universe, we propose dark matter with self-interactions characterized by a negative pressure; there is no vacuum energy whatsoever in this Cardassian model. These self-interactions may arise due…
We focus on the complex relationship between the shape of dark matter halos and the cosmological models underlying their formation. We used three realistic cosmological models from the Dark Energy Universe Simulation suite. They have…
By incorporating the holographic principle in a time-depending Lambda-term cosmology, new physical bounds on the arbitrary parameters of the model can be obtained. Considering then the dark energy as a purely geometric entity, for which no…
The current accelerated expansion of our universe could be due to an unknown energy component (dark energy) or a modification to general relativity (modified gravity). In the literature, it has been proposed that combining the probes of the…