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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

Small-scale challenges to $\Lambda$CDM cosmology require a deeper understanding of dark matter physics.This paper aims to develop maximum entropy distributions for dark matter particle velocity (denoted by $X$), speed (denoted by $Z$), and…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-06 Zhijie Xu

The mass profiles of massive dark matter halos are highly sensitive to the nature of dark matter and potential modifications of the theory of gravity on large scales. The $\Lambda$CDM paradigm makes strong predictions on the shape of dark…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-06 D. Eckert , S. Ettori , E. Pointecouteau , R. F. J. van der Burg , S. I. Loubser

The formation and structure of dark matter (DM) halos is studied by means of constrained realizations of Gaussian fields using N-body simulations. A series of experiments of the formation of a 10^{12} Msun halo is designed to study the…

An analysis of voids using cosmological N-body simulations of cold dark matter models is presented. It employs a robust statistics of voids, that was recently applied to discriminate between data from the Las Campanas Redshift Survey and…

Astrophysics · Physics 2009-11-07 S. Arbabi-Bidgoli , V. Mueller

We investigate the density profiles and evolution of weakly self-interacting cold dark matter haloes using a numerical code based on the collisional Boltzmann equation. This approach is alternative to N-body techniques in following the…

Astrophysics · Physics 2012-07-07 C. Firmani , E. D'Onghia , G. Chincarini

We investigate a self-interacting dark matter (SIDM) model featuring a velocity-dependent cross section with an order-of-magnitude resonant enhancement of the cross section at $\sim 16\,{\rm km}\,{\rm s}^{-1}$. To understand the…

Astrophysics of Galaxies · Physics 2024-09-02 Vinh Tran , Daniel Gilman , Mark Vogelsberger , Xuejian Shen , Stephanie O'Neil , Xinyue Zhang

We use the high-resolution Aquarius cosmological dark matter simulations coupled to the semi-analytic model by Starkenburg et al. (2013) to study the HI content and velocity width properties of field galaxies at the low mass end in the…

Astrophysics of Galaxies · Physics 2016-02-17 C. Y. Yaryura , A. Helmi , M. G. Abadi , E. Starkenburg

The current knowledge of cosmological structure formation suggests that Cold Dark Matter (CDM) halos possess a nonspherical density profile, implying that cosmic structures can be potential sources of gravitational waves via power transfer…

Astrophysics · Physics 2007-05-23 Carmelita Carbone , Carlo Baccigalupi , Sabino Matarrese

We use a set of high-resolution cosmological N-body simulations to investigate the inner mass profile of galaxy-sized cold dark matter (CDM) halos. These simulations extend the thorough numerical convergence study presented in Paper I of…

We quantify the impact of galaxy formation on dark matter halo shapes using cosmological simulations at redshift $z=0$. The haloes are drawn from the IllustrisTNG project, a suite of magneto-hydrodynamic simulations of galaxies. We focus on…

Astrophysics of Galaxies · Physics 2022-08-03 Kun Ting Eddie Chua , Mark Vogelsberger , Annalisa Pillepich , Lars Hernquist

Fuzzy dark matter (FDM) made of ultra-light bosonic particles is a viable alternative to cold dark matter (CDM) with clearly distinguishable small-scale features in collapsed structures. On large scales, it behaves gravitationally like CDM…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-11 Bodo Schwabe , Jens C. Niemeyer

The statistical mechanics of N cold dark matter (CDM) particles interacting via a softened gravitational potential is reviewed in the microcanonical ensemble and mean-field limit. A phase diagram for the system is computed as a function of…

Astrophysics · Physics 2014-10-13 Cathryn M. Trott , Andrew Melatos

We study the nonlinear growth of structure in nonlocal gravity models with the aid of N-body simulation and the spherical collapse and halo models. We focus on a model in which the inverse-squared of the d'Alembertian operator acts on the…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-25 Alexandre Barreira , Baojiu Li , Wojciech A. Hellwing , Carlton M. Baugh , Silvia Pascoli

Scalar Field Dark Matter (SFDM), comprised of ultralight ($\gtrsim 10^{-22}$ eV) bosons, is distinguished from massive ($\gtrsim$ GeV), collisionless Cold Dark Matter (CDM) by its novel structure-formation dynamics as Bose-Einstein…

Astrophysics of Galaxies · Physics 2021-05-26 Sonja O. Schobesberger , Tanja Rindler-Daller , Paul R. Shapiro

Constraints on dark matter halo masses from weak gravitational lensing can be improved significantly by using additional information about the morphology of their density distribution, leading to tighter cosmological constraints derived…

A type of exponential correction to General Relativity gives viable modified gravity model of dark energy. The model behaves as $R-2\Lambda$ at large curvature where an effective cosmological constant appears, but it becomes zero in flat…

General Relativity and Quantum Cosmology · Physics 2022-01-13 L. N. Granda

We use numerical simulations in a Lambda CDM cosmology to model density profiles in a set of 16 dark matter haloes with resolutions of up to 7 million particles within the virial radius. These simulations allow us to follow robustly the…

We present the largest collisionless $N$-body cosmological simulations in a MOdified Newtonian Dynamics (MOND) cosmology to date. Our 4 simulations cover $\Lambda$CDM as a baseline, a MOND with hot dark matter model known as $\nu$HDM, and 2…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-17 Alfie Russell , Indranil Banik , Oscar Cray , Hongsheng Zhao

Aims. We investigate the gravitational redshift in clusters of galaxies in the symmetron and Hu-Sawicky $f(R)$ models. The characteristic feature of both models is the screening mechanism that hides the fifth force in dense environments…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-05 Max B. Gronke , Claudio Llinares , David F. Mota