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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

Understanding the non-linear dynamics of satellite halos (a.k.a. "sub-halos") is important for predicting the abundance and distribution of dark matter substructures and satellite galaxies, and for distinguishing among microphysical dark…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-25 Shengqi Yang , Xiaolong Du , Andrew J. Benson , Anthony R. Pullen , Annika H. G. Peter

The internal structure and abundance of dark matter halos and subhalos are powerful probes of the nature of dark matter. In order to compare observations with dark matter models, accurate theoretical predictions of these quantities are…

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

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

Within the framework of hierarchical clustering we show that a simple Press-Schechter-like approximation, based on spherical dynamics, provides a good estimate of the evolution of the density field in the quasi-linear regime up to $\Sigma…

Astrophysics · Physics 2007-05-23 P. Valageas

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

We present the nonlinear growth of bound cosmological structures using the spherical collapse approach in the shift-symmetric Galileon theories. In particular, we focus on the class of models belonging to the Kinetic Gravity Braiding by…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-09 Inês S. Albuquerque , Noemi Frusciante , Francesco Pace , Carlo Schimd

The mean matter density within the turnaround radius, which is the boundary that separates a nonexpanding structure from the Hubble flow, was recently proposed as a novel cosmological probe. According to the spherical collapse model, the…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-14 Giorgos Korkidis , Vasiliki Pavlidou , Konstantinos Tassis

Accurately predicting the abundance and structural evolution of dark matter subhaloes is crucial for understanding galaxy formation, modeling galaxy clustering, and constraining the nature of dark matter. Due to the nonlinear nature of…

Astrophysics of Galaxies · Physics 2019-10-22 Sheridan B. Green , Frank C. van den Bosch

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

We generalize the spherical collapse model for the formation of dark matter halos to apply in a universe with arbitrary positive cosmological constant. We calculate the critical condition for collapse of an overdense region and give exact…

Astrophysics · Physics 2016-11-03 Ewa L. Lokas , Y. Hoffman

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.…

Astrophysics · Physics 2009-11-10 D. F. Mota , C. van de Bruck

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

In this paper I consider the nonlinear evolution of a rare density fluctuation in a random density field with Gaussian fluctuations, and I rigorously show that it follows the spherical collapse dynamics applied to its mean initial profile.…

Astrophysics · Physics 2009-10-22 F. Bernardeau

We investigate the structure of cold dark matter halos using advanced models of spherical collapse and accretion in an expanding Universe. These base on solving time-dependent equations for the moments of the phase-space distribution…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 A. Lapi , A. Cavaliere

We examine the cosmological redshift-space distortion effect on the power spectrum of the objects at high-redshifts, which is an unavoidable observational contamination in general relativistic cosmology. In particular, we consider the…

Astrophysics · Physics 2009-10-31 Hiromitsu Magira , Y. P. Jing , Yasushi Suto

We develop a skew-adaptive extension of split conformal prediction for regression. The method starts from an asymmetric interval family centered at a point prediction and uses the gauge approach to deduce the conformity score induced by…

Machine Learning · Statistics 2026-05-18 Paulo C. Marques F. , Helton Graziadei

We present a comparative analysis of several methods, known as local Lagrangian approximations, which are aimed to the description of the nonlinear evolution of large-scale structure. We have investigated various aspects of these…

Astrophysics · Physics 2009-11-06 Martin Makler , Takeshi Kodama , Mauricio O. Calvao

We study the behaviour of the density contrast in quasi-spherical Szekeres spacetime and derive its analytical behaviour as a function of $t$ and $r$. We set up the inhomogeneity using initial data in the form of one extreme value of the…

General Relativity and Quantum Cosmology · Physics 2014-12-24 David Vrba , Otakar Svitek