English
Related papers

Related papers: An Improved Semi-Analytical Spherical Collapse Mod…

200 papers

We present a novel route to constructing cost-efficient semi-empirical approximations for the non-additive kinetic energy in subsystem density functional theory. The developed methodology is based on the use of Slater determinants composed…

Chemical Physics · Physics 2025-01-13 Larissa Sophie Eitelhuber , Denis G. Artiukhin

It has been shown some years ago that dark matter haloes outskirts are characterized by very steep density profiles in a very small radial range. This feature has been interpreted as a pile up of at a similar location of different particle…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-29 Antonino Del Popolo , Morgan Le Delliou

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

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

We study the sensitivity of weak lensing by large scale structures to the evolution of dark energy. We explore a 2-parameters model of dark energy evolution, inspired by tracking quintessence models. To this end, we compute the likelihood…

Astrophysics · Physics 2008-11-26 Karim Benabed , Ludovic Van Waerbeke

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

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

Using weakly nonlinear conditional PDF for the density field around an overdense region we find that the expected density contrast around a peak is always smaller while its rms fluctuation larger than in the linear case. We apply these…

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

In relativistic cosmology, the formation of nonlinear inhomogeneities can induce non-negligible backreaction on late-time expansion. Among the important consequences for precision cosmology is the potential impact on the linear growth of…

General Relativity and Quantum Cosmology · Physics 2026-04-27 Marco Galoppo , Pierre Mourier

A semi--numerical approach proposed many years ago for describing gravitational collapse in the post--quasi--static approximation, is modified in order to avoid the numerical integration of the basic differential equations the approach is…

General Relativity and Quantum Cosmology · Physics 2024-03-13 L. Herrera , A. Di prisco , J. Ospino

Cosmological Perturbation Theory (PT) is a useful tool to study the cumulants of the density and velocity fields in the large scale structure of the Universe. In Papers I & II of this series we saw that the Spherical Collapse (SC) model…

Astrophysics · Physics 2009-10-30 P. Fosalba , E. Gaztanaga

In Part I of this series, we introduced the Spherical Collapse (SC) approximation in Lagrangian space as a way of estimating the cumulants $\xi_J$ of density fluctuations in cosmological Perturbation Theory (PT). Within this approximation,…

Astrophysics · Physics 2009-10-30 Enrique Gaztanaga , Pablo Fosalba

The abundance and demographics of dark matter substructure is important for many areas in astrophysics and cosmological $N$-body simulations have been the primary tool used to investigate them. However, it has recently become clear that the…

Astrophysics of Galaxies · Physics 2019-03-19 Go Ogiya , Frank C. van den Bosch , Oliver Hahn , Sheridan B. Green , Tim B. Miller , Andreas Burkert

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 investigate a spherical overdensity model for the non-clustering dark energy (DE) with the constant equation of state, w in a flat universe. In this case, the exact solution for the evolution of the scale factor is obtained for general…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-27 Seokcheon Lee , Kin-Wang Ng

We perform a linear perturbation analysis of expanding shells driven by expansions of HII regions. The ambient gas is assumed to be uniform. As an unperturbed state, we develop a semi-analytic method for deriving the time evolution of the…

Astrophysics of Galaxies · Physics 2015-05-27 Kazunari Iwasaki , Shu-ichiro Inutsuka , Toru Tsuribe

Sparse regression and classification estimators that respect group structures have application to an assortment of statistical and machine learning problems, from multitask learning to sparse additive modeling to hierarchical selection.…

Methodology · Statistics 2024-03-11 Ryan Thompson , Farshid Vahid

In this letter, we study the late-time evolution of a torsion cosmology only with the spin-$0^+$ mode. We find three kinds of analytical solutions with a constant affine scalar curvature. In the first case, it is not physical because the…

General Relativity and Quantum Cosmology · Physics 2019-08-17 Xi-chen Ao , Xin-zhou Li , Ping Xi

Semiparametric regression offers a flexible framework for modeling non-linear relationships between a response and covariates. A prime example are generalized additive models where splines (say) are used to approximate non-linear functional…

Statistics Theory · Mathematics 2018-10-05 Francis K. C. Hui , Chong You , Han Lin Shang , Samuel Müller

A dynamical symmetry for spherical collapse has been studied using a linear transformation of the initial data set (mass and kinetic energy function) and the area radius. With proper choice of the initial area radius, the evolution as well…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Subenoy Chakraborty , Asit Banerjee , Ujjal Debnath