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Related papers: Effects of shear and rotation on the spherical col…

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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

We study the spherical collapse model in the presence of external gravitational tidal shear fields for different dark energy scenarios and investigate the impact on the mass function and cluster number counts. While previous studies of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-12 Robert Reischke , Francesco Pace , Sven Meyer , Björn Malte Schäfer

Traditionally the spherical collapse of objects is studied with respect to a uniform background density, yielding the critical over-density $\delta_\mathrm{c}$ as key ingredient to the mass function of virialized objects. Here we…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-26 Robert Reischke , Francesco Pace , Sven Meyer , Björn Malte Schäfer

We extend a previous work by Reischke et al., 2016 by studying the effects of tidal shear on clustering dark energy models within the framework of the extended spherical collapse model and using the Zel'dovich approximation. As in previous…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 Francesco Pace , Robert Reischke , Sven Meyer , Björn Malte Schäfer

We study the gravitational clustering of spherically symmetric overdensities and the statistics of the resulting dark matter halos in the "symmetron model", in which a new long range force is mediated by a $Z_2$ symmetric scalar field.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Laura Taddei , Riccardo Catena , Massimo Pietroni

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

Under the commonly used spherical collapse model, we study how dark energy affects the growth of large scale structures of the Universe in the context of agegraphic dark energy models. The dynamics of the spherical collapse of dark matter…

General Relativity and Quantum Cosmology · Physics 2017-10-11 M. Rezaei , M. Malekjani

The evolution of the virial overdensity $\Delta_{\rm vir}$ for $\Lambda$CDM and seven dynamical dark-energy models is investigated in the extended spherical collapse model (SCM). Here the virialization process is naturally achieved by…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-10 Francesco Pace , Carlo Schimd , David F. Mota , Antonino Del Popolo

In this paper, we present a simulation method within the two-component spherical collapse model to investigate dark energy perturbations associated with the formation of dark matter halos. The realistic mass accretion history of a dark…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Qiao Wang , Zuhui Fan

We compute the critical density of collapse for spherically symmetric overdensities in a class of f(R) modified gravity models. For the first time we evolve the Einstein, scalar field and non-linear fluid equations, making the minimal…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-26 Michael Kopp , Stephen A. Appleby , Ixandra Achitouv , Jochen Weller

We explore the impact of a LWDM cosmological scenario on the clustering properties of large-scale structure in the Universe. We do this by extending the halo model. The new development is that we consider two components to the mass density:…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-29 Robert E. Smith , Katarina Markovic

We study the nonlinear evolution of matter overdensities using the spherical collapse model in degenerate higher-order scalar-tensor (DHOST) theories beyond Horndeski, employing the effective field theory (EFT) of dark energy approach. We…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-18 Toshiki Takadera , Takashi Hiramatsu , Tsutomu Kobayashi

In this work we review the theory of the spherical collapse model and critically analyse the aspects of the numerical implementation of its fundamental equations. By extending a recent work by Herrera et al. 2017, we show how different…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-21 Francesco Pace , Sven Meyer , Matthias Bartelmann

The present work deals with the spherical collapse of matter overdensity for two reconstructed dark energy models. One of the models is reconstructed from parametrization of effective or total equation of state of energy components in the…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-18 Ankan Mukherjee

We investigate the clustering effect of dark energy (DE) in the formation of galaxy clusters using the spherical collapse model. Assuming a fully clustered DE component, the spherical overdense region is treated as an isolated system which…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-02 Chia-Chun Chang , Wolung Lee , Kin-Wang Ng

The abundance of massive dark matter halos hosting galaxy clusters provides an important test of the masses of relic neutrino species. The dominant effect of neutrino mass is to lower the typical amplitude of density perturbations that…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-03 Marilena LoVerde

We consider a generic type of dark energy fluid, characterised by a constant equation of state parameter w and sound speed c_s, and investigate the impact of dark energy clustering on cosmic structure formation using the spherical collapse…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Tobias Basse , Ole Eggers Bjaelde , Yvonne Y. Y. Wong

We present a comprehensive analysis of the halo model of cosmological large to small-scale structure statistics in the case of warm dark matter (WDM) structure formation scenarios. We include the effects of WDM on the linear matter power…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-29 Robyn M. Dunstan , Kevork N. Abazajian , Emil Polisensky , Massimo Ricotti

We use large N-body simulations of dissipationless gravitational clustering in cold dark matter (CDM) cosmologies to study whether the properties of dark matter halos are affected by their environment. We look for correlations between the…

Astrophysics · Physics 2009-09-25 Gerard Lemson , Guinevere Kauffmann

While in the standard cosmological model the accelerated expansion of the Universe is explained by invoking the presence of the cosmological constant term, it is still unclear the true origin of this stunning observational fact. It is…

General Relativity and Quantum Cosmology · Physics 2015-10-07 Mohammad Malekjani , Tayebe Naderi , Francesco Pace
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