منابع مشابه
Some improvements to the spherical collapse model
I study the joint effect of dynamical friction, tidal torques and cosmological constant on clusters of galaxies formation. I show that within high-density environments, such as rich clusters of galaxies, both dynamical friction and tidal torques slows down the collapse of low-ν peaks producing an observable variation in the time of collapse of the perturbation and, as a consequence, a reduction...
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In this work, we study the formation and evolution of dark matter halos by means of the spherical infall model with shell-crossing. We present a framework to tackle this effect properly, that does not involve the adiabatic approximation, and is based on the numerical follow-up, with time, of that individual shell of matter that contains always the same fraction of mass with respect to the total...
متن کاملSpherical collapse model with and without curvature
We investigate a spherical collapse model with and without the spatial curvature. We obtain the exact solutions of dynamical quantities such as the ratio of the scale factor to its value at the turnaround epoch (x ≡ a ata ) and the ratio of the overdensity radius to its value at the turnaround time (y ≡ R Rta ) with general cosmological parameters. The exact solutions of the overdensity at the ...
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We study the spherical collapse model in dark energy cosmologies, in which dark energy is modelled as a minimally coupled scalar field. We first follow the standard assumption that dark energy does not cluster on the scales of interest. Investigating four different popular potentials in detail, we show that the predictions of the spherical collapse model depend on the potential used. We also in...
متن کاملThe Spherical Collapse Model in a Universe with Cosmological Constant
The spherical collapse model was first developed by Gunn & Gott 1 for a flat universe with no cosmological constant. It assumes that the process of formation of bound objects in the universe can be at first approximation described by evolution of an uniformly overdense spherical region in otherwise smooth background. Despite its simplicity, the model has been widely used to explain properties o...
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ژورنال
عنوان ژورنال: Journal of Physics: Conference Series
سال: 2013
ISSN: 1742-6588,1742-6596
DOI: 10.1088/1742-6596/470/1/012006