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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 study the growth of cold dark matter density perturbations in the nonlinear regime on a conformally coupled quintessence model in which the background is designed to mimic a $\Lambda$CDM cosmology. The spherical collapse of…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-03 Bruno J. Barros , Tiago Barreiro , Nelson J. Nunes

Using the spherical collapse approach, we investigate the impact of two alternative dark matter models, each characterized by distinct non-zero equations of state, one constant and the other time dependent on the nonlinear regime.…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-22 Zahra Davari , Amjad Ashoorioon , Kazem Rezazadeh

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

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 quintessence with negligible speed of sound. This case is particularly motivated for w<-1 as it is required by stability. As pressure gradients are negligible, quintessence follows…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Paolo Creminelli , Guido D'Amico , Jorge Noreña , Leonardo Senatore , Filippo Vernizzi

We present a double distribution function of dark matter halos, with respect to both object mass and local over- (or under-) density. This analytical tool provides a statistical treatment of the properties of matter surrounding collapsed…

Astrophysics · Physics 2009-11-10 Vasiliki Pavlidou , Brian D. Fields

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

In the framework of the spherical collapse model we study the influence of shear and rotation terms for dark matter fluid in clustering dark energy models. We evaluate, for different equations of state, the effects of these terms on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 F. Pace , R. C. Batista , A. Del Popolo

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

We investigate the cosmological evolution of mimetic matter model with arbitrary scalar potential. The cosmological reconstruction, which is the way to construct a model for arbitrary evolutions of the scale factor, is explicitly done for…

General Relativity and Quantum Cosmology · Physics 2015-04-01 Jiro Matsumoto , Sergei D. Odintsov , Sergey V. Sushkov

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 intend to understand cosmological structure formation within the framework of superfluid models of dark matter with finite temperatures. Of particular interest is the evolution of small-scale structures where the pressure and superfluid…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-28 S. T. H. Hartman , H. A. Winther , D. F. Mota

Structure formation provides a strong test of any cosmic acceleration model because a successful dark energy model must not inhibit {\black or overpredict} the development of observed large-scale structures. Traditional approaches to…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-28 C. Prescod-Weinstein , N. Afshordi

In existing literatures about the top-hat spherical collapse model of galaxy clusters formation in cosmology containing dark energies, dark energies are usually assumed not to cluster on this scale. But all these literatures ignored the…

Astrophysics · Physics 2016-08-30 Ding-fang Zeng , Yi-hong Gao

We studied the spherical collapse model in the flat $\Lambda$CDM cosmology and provided exact and analytical formulaes for the calculation of the two important parameters in the application of Press-Schechter theory, the critical density…

Astrophysics · Physics 2007-05-23 Ding-fang Zeng , Yi-hong Gao

In this work we investigate the spherical collapse model in flat FRW dark energy universes. We consider the Holographic Dark Energy (HDE) model as a dynamical dark energy scenario with a slowly time-varying equation-of-state (EoS) parameter…

General Relativity and Quantum Cosmology · Physics 2015-01-27 Tayebe Naderi , Mohammad Malekjani , Francesco Pace

Sheth-Tormen mass function has been widely used to quantify the abundance of dark matter halos. It is a significant improvement over the Press-Schechter mass function as it uses ellipsoidal collapse in place of spherical collapse. Both of…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-05 Swati Gavas , J S Bagla , Nishikanta Khandai , Girish Kulkarni

Understanding the influence of dark energy on the formation of structures is currently a major challenge in Cosmology, since it can distinguish otherwise degenerated viable models. In this work we consider the Top-Hat Spherical-Collapse…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-19 D. Herrera , I. Waga , S. E. Jorás

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
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