English
Related papers

Related papers: Spherical collapse in reconstructed dark energy mo…

200 papers

In this work, we study the collapse dynamics of an inhomogeneous spherically symmetric star made of dark matter (DM) and dark energy (DE). The dark matter is taken in the form of a dust cloud while anisotropic fluid is chosen as the…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Subenoy Chakraborty , Tanwi Bandyopadhyay

The free-streaming length of dark matter depends on fundamental dark matter physics, and determines the abundance and concentration of dark matter halos on sub-galactic scales. Using the image positions and flux ratios from eight…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Daniel Gilman , Simon Birrer , Anna Nierenberg , Tommaso Treu , Xiaolong Du , Andrew Benson

Deep multi-color galaxy surveys with photometric redshifts will provide a large number of two-point correlation observables: galaxy-galaxy angular correlations, galaxy-shear cross correlations, and shear-shear correlations between all…

Astrophysics · Physics 2008-11-26 Wayne Hu , Bhuvnesh Jain

We study cosmological perturbations in a model of unified dark matter and dark energy with a sharp transition in the late-time universe. The dark sector is described by a dark fluid which evolves from an early stage at redshifts $z > z_C$…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-05 Rodrigo R. Cuzinatto , Léo G. Medeiros , Eduardo M. de Morais , Robert H. Brandenberger

We describe a methodology to accurately compute halo mass functions, progenitor mass functions, merger rates and merger trees in non-cold dark matter universes using a self-consistent treatment of the generalized extended Press-Schechter…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Andrew J. Benson , Arya Farahi , Shaun Cole , Leonidas A. Moustakas , Adrian Jenkins , Mark Lovell , Rachel Kennedy , John Helly , Carlos Frenk

The cosmological constant $\Lambda$ and cold dark matter (CDM) model ($\Lambda\text{CDM}$) is one of the pillars of modern cosmology and is widely used as the de facto theoretical model by current and forthcoming surveys. As the nature of…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-08 Rubén Arjona , Alessandro Melchiorri , Savvas Nesseris

We use the moments of counts of neighbors as given by the Generalized Correlation Integrals, to study the clustering properties of Dark Matter Halos (DH) in Cold Dark Matter (CDM) and Cold+Hot Dark Matter (CHDM) models. We compare the…

Astrophysics · Physics 2016-08-30 A. Campos , G. Yepes , A. Klypin , G. Murante , A. Provenzale , S. Borgani

In this second paper we present the first Nbody cosmological simulations of strongly coupled Dark Energy models (SCDEW), a class of models that alleviates theoretical issues related to the nature of dark energy. SCDEW models assume a strong…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-09 Andrea V. Macciò , Roberto Mainini , Camilla Penzo , Silvio A. Bonometto

The recent observational evidence for the current cosmic acceleration have stimulated renewed interest in alternative cosmologies, such as scenarios with interaction in the dark sector (dark matter and dark energy). In general, such models…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-22 R. S. Goncalves , J. S. Alcaniz , A. Dev , D. Jain

The top-hat spherical collapse model (TSC) is one of the most fundamental analytical frameworks to describe the non-linear growth of cosmic structure. TSC has motivated, and been widely applied in, various researches even in the current era…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-20 Daichi Suto , Tetsu Kitayama , Ken Osato , Shin Sasaki , Yasushi Suto

We use the spherical collapse (SC) approximation to derive expressions for the smoothed redshift-space probability distribution function (PDF), as well as the $p$-order hierarchical amplitudes $S_p$, in both real and redshift space. We…

Astrophysics · Physics 2009-11-06 Robert J. Scherrer , Enrique Gaztanaga

It has been recently shown that cosmological models with scale-dependent primordial non-Gaussianities (sPNG) could provide a possible path to solve current cosmic tensions. Moreover, it has been pointed out that some of these models might…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-08 Clément Stahl , Benoit Famaey , Rodrigo Ibata , Katarina Kraljic , Fabien Castillo

In the excursion set approach to structure formation initially spherical regions of the linear density field collapse to form haloes of mass $M$ at redshift $z_{\rm id}$ if their linearly extrapolated density contrast, averaged on that…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-07 Aaron D. Ludlow , Mikolaj Borzyszkowski , Cristiano Porciani

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 derive a semi-analytical extension of the spherical collapse model of structure formation that takes account of the effects of deviations from spherical symmetry and shell crossing which are important in the non-linear regime. Our model…

Astrophysics · Physics 2008-11-26 Douglas J. Shaw , David F. Mota

Despite the ever growing observational evidence for the existence of the large scale magnetic fields, their origin and the evolution are not fully understood. If the magnetic fields are of primordial origin, they result in the generation of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Yuki Shibusawa , Kiyotomo Ichiki , Kenji Kadota

We use the physics of ellipsoidal collapse to model the probability distribution function of the smoothed dark matter density field in real and redshift space. We provide a simple approximation to the exact collapse model which shows…

Astrophysics · Physics 2008-08-05 Tsz Yan Lam , Ravi K. Sheth

We study the formation of dark matter halos in the concordance LCDM model over a wide range of redshifts, from z=20 to the present. Our primary focus is the halo mass function, a key probe of cosmology. By performing a large suite of…

Astrophysics · Physics 2008-11-26 Zarija Lukic , Katrin Heitmann , Salman Habib , Sergei Bashinsky , Paul M. Ricker

The late stages of large-scale structure evolution are treated semi-analytically within the framework of modified halo model. We suggest simple yet accurate approximation for relating the non-linear amplitude to linear one for spherical…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-10 Yurij Kulinich , Bohdan Novosyadlyj , Stepan Apunevych

I apply the modified spherical infall model to test the dependence of the shape of density profiles of dark matter halos on redshift. The model predicts that the density profile of a halo of a given mass steepens with time and its…

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