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Related papers: Multi-Dimensional Density Estimation and Phase Spa…

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We present a method for computing the 6-dimensional coarse-grained phase-space density $f(x,v)$ in an N-body system, and derive its distribution function $v(f)$. The method is based on Delaunay tessellation, where $v(f)$ is obtained with an…

Astrophysics · Physics 2009-11-10 I. Arad , A. Dekel , A. Klypin

The properties of the matter density field in the initial conditions have a decisive impact on the features of the large-scale structure of the Universe as observed today. These need to be studied via $N$-body simulations, which are…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-21 Jazhiel Chacón , Isidro Gómez-Vargas , Ricardo Menchaca Méndez , José Alberto Vázquez

We use dissipationless N-body simulations to investigate the evolution of the true coarse-grained phase-space density distribution f(x,v) in equal-mass mergers between dark matter (DM) halos. The halo models are constructed with various…

Astrophysics · Physics 2011-02-11 Ileana M. Vass , Stelios Kazantzidis , Monica Valluri , Andrey V. Kravtsov

At early times dark matter has a thermal velocity dispersion of unknown amplitude which, for warm dark matter models, can influence the formation of nonlinear structure on observable scales. We propose a new scheme to simulate cosmologies…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-10 Jens Stücker , Oliver Hahn , Raul E. Angulo , Simon D. M. White

(Shortened) We use N-body simulations to investigate the structure and dynamical evolution of dark matter halos in galaxy clusters. Our sample consists of nine massive halos from an EdS universe with scale free power spectrum and n = -1.…

Astrophysics · Physics 2015-06-24 Giuseppe Tormen , Francois R. Bouchet , Simon D. M. White

We present the implementation of a halo based method for the reconstruction of the cosmic mass density field. The method employs the mass density distribution of dark matter haloes and its environments computed from cosmological N-body…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 J. C. Muñoz-Cuartas , V. Mueller , J. Forero-Romero

We report a series of high-resolution cosmological N-body simulations designed to explore the formation and properties of dark matter halos with masses close to the damping scale of the primordial power spectrum of density fluctuations. We…

Astrophysics · Physics 2009-11-13 P. Colin , O. Valenzuela , V. Avila-Reese

We introduce a new method to calculate dark matter halo density profiles from simulations. Each particle is 'smeared' over its orbit to obtain a dynamical profile that is averaged over a dynamical time, in contrast to the traditional…

Astrophysics of Galaxies · Physics 2024-01-26 Claudia Muni , Andrew Pontzen , Jason L. Sanders , Martin P. Rey , Justin I. Read , Oscar Agertz

The density profiles of dark matter haloes can potentially probe dynamics, fundamental physics, and cosmology, but some of the most promising signals reside near or beyond the virial radius. While these scales have recently become…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-29 Benedikt Diemer

We present a new and completely general technique for calculating the fine-grained phase-space structure of dark matter throughout the Galactic halo. Our goal is to understand this structure on the scales relevant for direct and indirect…

Astrophysics · Physics 2009-11-13 Mark Vogelsberger , Simon D. M. White , Amina Helmi , Volker Springel

We develop a new method to reconstruct the cosmic density field from the distribution of dark matter haloes above a certain mass threshold. Our motivation is that well-defined samples of galaxy groups/clusters, which can be used to…

Astrophysics · Physics 2009-11-13 H. Y. Wang , H. J. Mo , Y. P. Jing , Y. C. Guo , Frank C. van den Bosch , X. H. Yang

[Abridged] We present a novel technique, dubbed FiEstAS, to estimate the underlying density field from a discrete set of sample points in an arbitrary multidimensional space. FiEstAS assigns a volume to each point by means of a binary tree.…

Astrophysics · Physics 2009-11-10 Y. Ascasibar , J. Binney

A new analysis method to investigate halos in finite many-fermion systems is designed, as existing characterization methods are proven to be incomplete/inaccurate. A decomposition of the internal wave-function of the {$N$-body} system in…

Nuclear Theory · Physics 2013-05-29 V. Rotival , T. Duguet

We use the Delaunay Tessellation Field Estimator (DTFE) to study the one-point density distribution functions of the Millennium (MS) and Millennium-II (MS-II) simulations. The DTFE technique is based directly on the particle positions,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Biswajit Pandey , Simon D. M. White , Volker Springel , Raul Angulo

A method is presented for computing the 6-D phase-space density f(x,v) and its PDF v(f) in an N-body system. It is based on Delaunay tessellation, yielding v(f) with a fixed smoothing window over a wide f range, independent of the sampling…

Astrophysics · Physics 2007-05-23 Avishai Dekel , Itai Arad

An ambitious goal in cosmology is to forward-model the observed distribution of galaxies in the nearby Universe today from the initial conditions of large-scale structures. For practical reasons, the spatial resolution at which this can be…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-18 Tom Charnock , Guilhem Lavaux , Benjamin D. Wandelt , Supranta Sarma Boruah , Jens Jasche , Michael J. Hudson

Understanding the nature of dark matter is among the top priorities of modern physics. However, due to its inertness, detecting and studying it directly in terrestrial experiments is extremely challenging. Numerical N-body simulations…

Astrophysics of Galaxies · Physics 2024-03-06 Zhen Li , Steen H. Hansen

We measure the Voronoi density probability distribution function (PDF) for both dark matter and halos in N-body simulations. For the dark matter, Voronoi densities represent the matter density field smoothed on a uniform mass scale, which…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 Drew Jamieson , Marilena Loverde

We present a deep-learning-based approach for identifying dark matter haloes in cosmological N-body simulations. Our framework consists of a volumetric Convolutional Neural Network to classify individual simulation particles as either halo…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-26 Soumadeep Maiti , Carlos M. Correa , Andrea Fiorilli , Andrés N. Ruiz , Dante J. Paz , Alejandro Pérez Fernández , Ariel G. Sánchez

We use N-body simulations to investigate the structure of dark halos in the standard Cold Dark Matter cosmogony. Halos are excised from simulations of cosmologically representative regions and are resimulated individually at high…

Astrophysics · Physics 2008-11-26 Julio F. Navarro , Carlos S. Frenk , Simon D. M. White
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