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(Abridged) We study the outer density profiles of dark matter haloes predicted by a generalized secondary infall model and observed in a N-body cosmological simulation of a \Lambda CDM model. We find substantial systematic variations in…

Astrophysics · Physics 2009-10-31 V. Avila-Reese , C. Firmani , A. Klypin , A. V. Kravtsov

We study the mass, velocity dispersion, and anisotropy profiles of $\Lambda$CDM halos using a suite of N-body simulations of unprecedented numerical resolution (the {\it Aquarius Project}). Our analysis confirms a number of results claimed…

We give a summary of recent results on spatial and velocity biases in cosmological models. Progress in numerical techniques made it possible to simulate halos in large volumes with a such accuracy that halos survive in dense environments of…

Astrophysics · Physics 2007-05-23 Anatoly Klypin

The cosmic curvature density parameter has been constrained in the present work independent of any background cosmological model. The reconstruction is performed adopting the non-parametric Gaussian Processes (GP). The constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-18 Purba Mukherjee , Narayan Banerjee

We employ high-resolution zoom-in cosmological simulations to analyze the emerging morphology of galaxies in dark matter halos at redshifts z > 2. We choose DM halos of similar masses of log (Mvir/Mo) ~11.65 +- 0.05 at the target redshifts…

Astrophysics of Galaxies · Physics 2022-02-23 Da Bi , Isaac Shlosman , Emilio Romano-Diaz

The abundance of dark matter haloes is one of the key probes of the growth of structure and expansion history of the Universe. Theoretical predictions for this quantity usually assume that, when expressed in a certain form, it depends only…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-22 Lurdes Ondaro-Mallea , Raul E. Angulo , Matteo Zennaro , Sergio Contreras , Giovanni Aricò

We present a proposal for the full phase space distribution of the Milky Way halo. The model is axially and reflection symmetric and its time evolution is self-similar. It describes the halo as a set of discrete dark matter flows with…

Astrophysics · Physics 2009-02-20 L. D. Duffy , P. Sikivie

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 use numerical relativity simulations to describe the spacetime evolution during nonlinear structure formation in $\Lambda$CDM cosmology. Fully nonlinear initial conditions are set at an initial redshift $z\approx 300$, based directly on…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 Robyn L. Munoz , Marco Bruni

An important part of cosmological model fitting relies on correlating distance indicators of objects (for example type Ia supernovae) with their redshift, often illustrated on a Hubble diagram. Comparing the observed correlation with a…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-22 Julian Adamek , Chris Clarkson , Louis Coates , Ruth Durrer , Martin Kunz

We employ a stochastic approach to probing the origin of the log-normal distributions of halo spin in N-body simulations. After analyzing spin evolution in halo merging trees, it was found that a spin change can be characterized by a…

Astrophysics of Galaxies · Physics 2015-09-09 Juhan Kim , Yun-Young Choi , Sungsoo S. Kim , Jeong-Eun Lee

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 follow the evolution of the galaxy population in a Lambda-CDM cosmology by means of high-resolution N-body simulations in which the formation of galaxies and their observable properties are calculated using a semi-analytic model. We…

Astrophysics · Physics 2009-11-06 A. J. Benson , C. S. Frenk , C. M. Baugh , S. Cole , C. G. Lacey

We explore how the splashback radius ($R_{\rm sp}$) of galaxy clusters, measured using the number density of the subhalo population, changes based on various selection criteria using the IllustrisTNG cosmological galaxy formation…

Astrophysics of Galaxies · Physics 2022-04-06 Stephanie O'Neil , Josh Borrow , Mark Vogelsberger , Benedikt Diemer

The distribution of galaxies, halo abundance, and peculiar velocities are influenced by non-linear gravitational interactions, making the study of non-linear evolution crucial for accurate cosmological predictions. We explore these aspects…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-24 Swati Gavas

Cosmic voids have emerged as powerful probes for cosmology, providing complementary information on the large-scale structure of the universe. We present the first application of a hydrodynamical framework to model the evolution of cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-23 Tommaso Moretti , Giovanni Verza , Noemi Frusciante , Francesco Pace

We have derived an analytical model for the postcollapse equilibrium structure of cosmological halos as nonsingular truncated isothermal spheres (TIS) and compared this model with observations and simulations of cosmological halos on all…

Astrophysics · Physics 2009-11-06 Ilian T. Iliev , Paul R. Shapiro

In this work, we study the evolution of Betti curves obtained by persistent-homological analysis of point clouds formed by halos in different cosmological $N$-body simulations. We show that they can be approximated with a scaled log-normal…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-20 Vitalii Tymchyshyn , Maksym Tsizh , Franco Vazza , Marco Baldi

We train a machine learning algorithm to learn cosmological structure formation from N-body simulations. The algorithm infers the relationship between the initial conditions and the final dark matter haloes, without the need to introduce…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-02 Luisa Lucie-Smith , Hiranya V. Peiris , Andrew Pontzen , Michelle Lochner

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