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In this work, we extend the model proposed by White concerning the post-collapse evolution of density peaks while considering the role of angular momentum. On a timescale smaller than the peak collapse, $t_{0}$, the inner regions of the…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-12 Antonino Del Popolo , Saeed Fakhry

We derive the asymptotic mass profile near the collapse center of an initial spherical density perturbation, $\delta \propto M^{-\epsilon}$, of collision-less particles with non-radial motions. We show that angular momenta introduced at the…

Astrophysics · Physics 2009-10-31 Adi Nusser

We test the Secondary Infall Model (SIM) by direct comparison with the results of N-body simulations. Eight cluster-size and six galactic-size dark matter haloes have been selected at $z=0$ and re-simulated with high resolution. Based on…

Astrophysics · Physics 2008-11-26 Y. Ascasibar , Y. Hoffman , S. Gottloeber

We study the cusp/core problem using a secondary infall model (SIM) that takes into account the effect of ordered and random angular momentum, dynamical friction and baryons adiabatic contraction. The model is applied to structures on…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 A. Del Popolo

The radial mass distribution of dark matter haloes is investigated within the framework of the spherical infall model. We present a new formulation of spherical collapse including non-radial motions, and compare the analytical profiles with…

Astrophysics · Physics 2009-11-10 Y. Ascasibar , G. Yepes , S. Gottloeber , V. Mueller

In the present paper, we improve the "Extended Secondary Infall Model" (ESIM) of Williams et al. (2004) to obtain further insights on the cusp/core problem. The model takes into account the effect of ordered and random angular momentum,…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-04 A. Del Popolo , P. Kroupa

We discuss the influence of the cosmological background density field on the spherical infall model. The spherical infall model has been used in the Press-Schechter formalism to evaluate the number abundance of clusters of galaxies, as well…

Astrophysics · Physics 2009-10-31 A. Taruya , J. Soda

We study, for the first time, how shear and angular momentum modify typical parameters of the spherical collapse model, in dark energy dominated universes. In particular, we study the linear density threshold for collapse…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-04 A. Del Popolo , F. Pace , J. A. S. Lima

The self-similar infall model (SSIM) is normally discussed in the context of radial orbits in spherical symmetry. However it is possible to retain the spherical symmetry while permitting the particles to move in Keplerian ellipses, each…

Astrophysics · Physics 2009-11-10 Morgan Le Delliou , Richard N Henriksen

The influence of the shear stress and angular momentum on the nonlinear spherical collapse model is discussed in the framework of the Einstein-de Sitter (EdS) and $\Lambda$CDM models. By assuming that the vacuum component is not clustering…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-11 Antonino Del Popolo , Francesco Pace , J. A. S. Lima

Our new formulation of the Spherical Collapse Model (SCM-L) takes into account the presence of angular momentum associated with the motion of galaxy groups infalling towards the centre of galaxy clusters. The angular momentum is responsible…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-30 Guido Cupani , Marino Mezzetti , Fabio Mardirossian

Using the formalism of the spherical infall model the structure of collapsed and virialized dark halos is calculated for a variety of scale-free initial conditions. In spite of the scale-free cosmological nature of the problem, the collapse…

Astrophysics · Physics 2009-10-31 Ewa L. Lokas , Yehuda Hoffman

I propose a modification of the spherical infall model for the evolution of density fluctuations with initially Gaussian probability distribution and scale-free power spectra. I introduce a generalized form of the initial density…

Astrophysics · Physics 2007-05-23 Ewa L. Lokas

Although high-resolution N-body simulations make robust empirical predictions for the density distribution within cold dark matter halos, these studies have yielded little physical insight into the origins of the distribution. We…

Astrophysics · Physics 2008-11-26 Liliya L. R. Williams , Arif Babul , Julianne J. Dalcanton

We use the secondary infall model described in Del Popolo (2009), which takes into account the effect of dynamical friction, ordered and random angular momentum, baryons adiabatic contraction and dark matter baryons interplay, to study how…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 A. Del Popolo

We assume that the amplitude of the caustics in redshift space is a sum of two components: the first one can be predicted by the spherical infall model with no random motion, and the second is due to the random motion distribution. Smooth…

Astrophysics · Physics 2009-11-06 Nicos Hiotelis

In this paper we develop a new semianalytical approach to quantifying the density profile of outer dark matter halos, motivated by the remarkable universality those profiles, for a wide range of dynamical parameters of the inner halos. We…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-07 Kyriakos Grammatikos , Vasiliki Pavlidou

The near universality of DM halo density profiles provided by N-body simulations has proven to be robust against changes in total mass density, power spectrum, and some forms of initial velocity dispersion. In this letter we study the…

Astrophysics of Galaxies · Physics 2018-08-21 Erik W. Lentz , Thomas R. Quinn , Leslie J. Rosenberg

We study the spherical collapse model for several dark energy scenarios using the fully nonlinear differential equation for the evolution of the density contrast within homogeneous spherical overdensities derived from Newtonian…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 F. Pace , J. -C. Waizmann , M. Bartelmann

I report on recent progress in our understanding of the structure of CDM halos, and in particular of the inner mass profile of galaxy-sized systems. Numerical simulations have consistently shown that the density profiles of CDM halos…

Astrophysics · Physics 2007-05-23 Julio F. Navarro
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