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I present an analysis of the density shapes of dark matter halos in LCDM and LWDM cosmologies. The main results are derived from a statistical sample of galaxy-mass halos drawn from a high resolution LCDM N-body simulation. Halo shapes show…

Astrophysics · Physics 2017-08-23 James S. Bullock

Lensing flux-ratio anomalies are most likely caused by gravitational lensing by small-scale dark matter structures. These anomalies offer the prospect of testing a fundamental prediction of the cold dark matter (CDM) cosmological model: the…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-20 D. D. Xu , Dominique Sluse , Liang Gao , Jie Wang , Carlos Frenk , Shude Mao , Peter Schneider

We compare the specific angular momentum profiles of virialized dark halos in cold dark matter (CDM) and warm dark matter (WDM) models using high-resolution dissipationless simulations. The simulations were initialized using the same set of…

Astrophysics · Physics 2009-11-07 James S. Bullock , Andrey V. Kravtsov , Pedro Colin

We discuss bulk viscous cosmological models. Since the bulk viscous pressure is negative, viable viscous cosmological scenarios with late time accelerated expansion can in principle be constructed. After discussing some alternative models…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-20 Hermano Velten

There is strong evidence that cosmological N-body simulations dominated by Warm Dark Matter (WDM) contain spurious or unphysical haloes, most readily apparent as regularly spaced low-mass haloes strung along filaments. We show that spurious…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 Chris Power , Aaron S. G. Robotham , Danail Obreschkow , Alexander Hobbs , Geraint F. Lewis

We present eight cosmological dark matter (DM)--only zoom-in simulations of a Milky Way--like system that include suppression of the linear matter power spectrum $P(k)$, and/or velocity-dependent DM self-interactions, as the third…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-17 Ethan O. Nadler , Rui An , Daneng Yang , Hai-Bo Yu , Andrew Benson , Vera Gluscevic

If the concordance $\Lambda$CDM model is a true description of the universe, it should also properly predict the properties and structure of dark matter haloes, where galaxies are born. Using N-body simulations with a broad scale of mass…

Astrophysics · Physics 2016-08-15 P. Nurmi , P. Heinämäki , E. Saar , M. Einasto , J. Holopainen , V. J. Martínez , J. Einasto

We present zoom-in N-body + Hydrodynamic simulations of dwarf central galaxies formed in Warm Dark Matter (WDM) halos with masses at present-day of $2-4\times 10^{10}$ \msun. Two different cases are considered, the first one when halo…

Astrophysics of Galaxies · Physics 2015-06-23 Pedro Colin , Vladimir Avila-Reese , Alejandro Gonzalez-Samaniego , Hector Velazquez

High-resolution N--body simulations show a remarkable similarity in the structure of dark matter halos formed through dissipationless hierarchical clustering. Independent of halo mass, power spectrum, and cosmological parameters, the…

Astrophysics · Physics 2008-02-03 Julio F. Navarro

The concentrations of the cuspy dark matter halos predicted by simulations of cold dark matter are related to the cosmology in which the halos form. Observational constraints on halo concentration therefore map into constraints on…

Astrophysics · Physics 2009-11-07 S. McGaugh , M. Barker , E. de Blok

A decade ago cosmological simulations of increasingly higher resolution were used to demonstrate that virialized regions of Cold Dark Matter (CDM) halos are filled with a multitude of dense, gravitationally-bound clumps. These dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Andrey V. Kravtsov

Based on a set of cosmological N-body simulations we analyze properties of the dark matter haloes (DM) in a galaxy mass range ($10^{11} - 10^{13} h^{-1}M_{\odot}$) in modified $\lcdm$ cosmology with additional dynamically screened scalar…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-31 Wojciech A. Hellwing

In a recent paper, Alimi & Koskas highlighted in $w$CDM models derived from general relativity (GR) (with Dark Energy Universe numerical simulation data), a cosmological invariance of the distribution of dark-matter (DM) halo shapes when…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-08 Remy Koskas , Jean-Michel Alimi

We study the non-linear structure formation in cosmology accounting for the quantum nature of the dark matter (DM) particles in the initial conditions at decoupling, as well as in the relaxation and stability of the DM halos. Differently…

Astrophysics of Galaxies · Physics 2022-03-14 Carlos R. Argüelles , Eduar A. Becerra-Vergara , Andreas Krut , Rafael Yunis , Jorge A. Rueda , Remo Ruffini

If the accelerated expansion of the Universe at the present epoch is driven by a dark energy scalar field, there may well be a non-trivial coupling between the dark energy and the cold dark matter (CDM) fluid. Such interactions give rise to…

Astrophysics · Physics 2014-11-18 Marco Baldi , Valeria Pettorino , Georg Robbers , Volker Springel

Celestial capture of dark matter provides a useful handle for constraining its particulate properties. The capture formalism is sensitive to the phase space distribution of dark matter in the vicinity of the celestial object. This article…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-21 Debajit Bose , Sambo Sarkar

Self-interacting dark matter (SIDM) theory predicts that dark matter halos experience core-collapse, a process where the halo's inner region rapidly increases in density and decreases in size. The N-body simulations used to study this…

We present BAHAMAS-SIDM, the first large-volume, (400/h Mpc)^3, cosmological simulations including both self-interacting dark matter (SIDM) and baryonic physics. These simulations are important for two primary reasons: 1) they include the…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-02 Andrew Robertson , David Harvey , Richard Massey , Vincent Eke , Ian G. McCarthy , Mathilde Jauzac , Baojiu Li , Joop Schaye

Numerical simulations play an important role in current astronomy researches. Previous dark-matter-only simulations have represented the large-scale structure of the Universe. However, nowadays, hydro-dynamical simulations with baryonic…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-09 Weiguang Cui , Youcai Zhang

Results from hydrodynamical SPH simulations of galaxy clusters are used to investigate the dependence of the final cluster X-ray properties on the numerical resolution and the assumed models for the physical gas processes. Two different…

Astrophysics · Physics 2009-11-07 R. Valdarnini