scholarly journals On the implementation of the spherical collapse model for dark energy models

2017 ◽  
Vol 2017 (10) ◽  
pp. 040-040 ◽  
Author(s):  
Francesco Pace ◽  
Sven Meyer ◽  
Matthias Bartelmann
Keyword(s):  
Dark Energy ◽  
Energy Models ◽  
Spherical Collapse ◽  
Collapse Model

scholarly journals A Short Review on Clustering Dark Energy

Universe ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 22
Author(s):  
Ronaldo C. Batista
Keyword(s):  
Dark Energy ◽  
Short Review ◽  
Linear Perturbation ◽  
Linear Evolution ◽  
Energy Models ◽  
Spherical Collapse ◽  
Collapse Model ◽  
Hubble Radius ◽  
Linear Perturbation Theory ◽  
The Impact

We review dark energy models that can present non-negligible fluctuations on scales smaller than Hubble radius. Both linear and nonlinear evolutions of dark energy fluctuations are discussed. The linear evolution has a well-established framework, based on linear perturbation theory in General Relativity, and is well studied and implemented in numerical codes. We highlight the main results from linear theory to explain how dark energy perturbations become important on the scales of interest for structure formation. Next, we review some attempts to understand the impact of clustering dark energy models in the nonlinear regime, usually based on generalizations of the Spherical Collapse Model. We critically discuss the proposed generalizations of the Spherical Collapse Model that can treat clustering dark energy models and their shortcomings. Proposed implementations of clustering dark energy models in halo mass functions are reviewed. We also discuss some recent numerical simulations capable of treating dark energy fluctuations. Finally, we summarize the observational predictions based on these models.

scholarly journals Evolution of spherical overdensities in new agegraphic dark energy model

2017 ◽  
Vol 26 (09) ◽  
pp. 1750101
Author(s):  
M. R. Setare ◽  
F. Felegary ◽  
F. Darabi
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Holographic Dark Energy ◽  
Frw Cosmology ◽  
Spherical Region ◽  
Agegraphic Dark Energy ◽  
New Agegraphic Dark Energy ◽  
Energy Models ◽  
Spherical Collapse ◽  
Collapse Model

We study the structure formation by investigating the spherical collapse model in the context of new agegraphic dark energy (NADE) model in flat FRW cosmology. We compute the perturbational quantities [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] for the NADE model and compare the results with those of EdS and [Formula: see text] models. We find that there is a dark energy-dominated universe at low redshifts and a matter-dominated universe at high redshifts in agreement with the observations. Also, the size of structures, the overdense spherical region, and the halo size in the NADE model are found to be smaller, denser, and larger than those of EdS and [Formula: see text] models. We compare our results with the results of tachyon scalar field and holographic dark energy models.

Improvements in the Spherical Collapse Model and Dark Energy Cosmologies

2014 ◽  
Vol 23 (3-4) ◽  
Author(s):  
A. Del Popolo
Keyword(s):  
Shear Stress ◽  
Angular Momentum ◽  
Dark Energy ◽  
Spherical Symmetry ◽  
Linear Density ◽  
Spherical Collapse ◽  
Collapse Model ◽  
Density Threshold ◽  
Stress Influence

AbstractIn the present paper, we study how the effects of deviations from spherical symmetry of a system, produced by angular momentum, and shear stress, influence typical parameters of the spherical collapse model, like the linear density threshold for collapse of the non-relativistic component (

scholarly journals Effects of shear and rotation on the spherical collapse model for clustering dark energy

2014 ◽  
Vol 445 (1) ◽  
pp. 648-659 ◽  
Author(s):  
Francesco Pace ◽  
Ronaldo C. Batista ◽  
Antonino Del Popolo
Keyword(s):  
Dark Energy ◽  
Spherical Collapse ◽  
Collapse Model

THE INFLUENCE OF DARK ENERGY ON THE LARGE SCALE STRUCTURE FORMATION

2010 ◽  
Vol 25 (11n12) ◽  
pp. 874-884 ◽  
Author(s):  
SEOKCHEON LEE
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Structure Formation ◽  
Poisson Distribution ◽  
Large Scale ◽  
Density Perturbation ◽  
Spherical Collapse ◽  
Collapse Model ◽  
Small Scales ◽  
Large Scale Structure Formation

Inhomogeneity at small scales (Mpcs) of our universe is manifest from observations. In regions smaller than 8h-1 Mpc galaxies tend to cluster instead of showing a Poisson distribution. The properties of the spherical collapse model which approximately depicts this nonlinearity of the density perturbation are investigated when there exits dark energy. The evolution of a spherical perturbation depends only on the initial critical overdensity threshold for the collapse, δc and its value approaches to 1.58 instead of the conventionally known 1.69 independent of the value of the equation of state of dark energy.

scholarly journals On the spherical collapse model in dark energy cosmologies

2004 ◽  
Vol 421 (1) ◽  
pp. 71-81 ◽  
Author(s):  
D. F. Mota ◽  
C. van de Bruck
Keyword(s):  
Dark Energy ◽  
Spherical Collapse ◽  
Collapse Model
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