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Related papers: Multi-mass schemes for collisionless N-body simula…

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We present a mean-field approach to simulating merging processes of two spherical collisionless stellar systems. This approach is realized with a self-consistent field (SCF) method in which the full spatial dependence of the density and…

Instrumentation and Methods for Astrophysics · Physics 2019-04-17 Shunsuke Hozumi , Masaki Iwasawa , Keigo Nitadori

We introduce a novel technique for constraining cosmological parameters and galaxy assembly bias using non-linear redshift-space clustering of galaxies. We scale cosmological N-body simulations and insert galaxies with the SubHalo Abundance…

We propose a simple and accurate method for computing analytically the mass correlation function for cold dark matter and scale-free models that fits N-body simulations over a range that extends from the linear to the strongly non-linear…

Astrophysics · Physics 2009-10-31 R. R. Caldwell , Roman Juszkiewicz , Paul J. Steinhardt , Francois Bouchet

We present a Nested Markov chain Monte Carlo (NMC) scheme for building equilibrium averages based on accurate potentials such as density functional theory. Metropolis sampling of a reference system, defined by an inexpensive but approximate…

Chemical Physics · Physics 2015-06-17 Jeff Leiding , Joshua D. Coe

Determining the dynamical mass profiles of dispersion-supported galaxies is particularly challenging due to projection effects and the unknown shape of their velocity anisotropy profile. Our goal is to develop a machine learning algorithm…

We discuss the performance of direct summation codes used in the simulation of astrophysical stellar systems on highly distributed architectures. These codes compute the gravitational interaction among stars in an exact way and have an…

Astrophysics · Physics 2008-11-26 Alessia Gualandris , Simon Portegies Zwart , Alfredo Tirado-Ramos

In these lecture notes, we describe the current state-of-the-art for numerical simulations of large-scale structure and galaxy formation. Numerical simulations play a central role in the preparation and the exploitation of large-scale…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-16 Romain Teyssier

Fast N-body PM simulations with a small number of time steps such as FastPM or COLA have been remarkably successful in modeling the galaxy statistics, but their lack of small scale force resolution and long time steps cannot give accurate…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-14 Biwei Dai , Yu Feng , Uros Seljak

A diffusion Monte Carlo algorithm is introduced that can determine the correct nodal structure of the wave function of a few-fermion system and its ground-state energy without an uncontrolled bias. This is achieved by confining signed…

Computational Physics · Physics 2020-02-05 Alexander A. Kunitsa , So Hirata

We present the UNIT $N$-body cosmological simulations project, designed to provide precise predictions for nonlinear statistics of the galaxy distribution. We focus on characterizing statistics relevant to emission line and luminous red…

A longstanding problem in galactic simulations is to resolve the dynamical friction (DF) force acting on massive black hole particles when their masses are comparable to or less than the background simulation particles. Many sub-grid models…

Astrophysics of Galaxies · Physics 2023-05-17 Linhao Ma , Philip F. Hopkins , Luke Zoltan Kelley , Claude-André Faucher-Giguère

Among dynamical modeling techniques, the made-to-measure (M2M) method for modeling steady-state systems is among the most flexible, allowing non-parametric distribution functions in complex gravitational potentials to be modeled efficiently…

Astrophysics of Galaxies · Physics 2017-11-28 Jo Bovy , Daisuke Kawata , Jason A. S. Hunt

Current models of galaxy formation applied to understanding the large-scale structure of the universe have two parts. The first is an accurate solution of the equations of motion for the dark matter due to gravitational clustering. The…

Astrophysics · Physics 2009-11-06 Roman Scoccimarro , Ravi K. Sheth

We describe some results obtained with N-MODY, a code for N-body simulations of collisionless stellar systems in modified Newtonian dynamics (MOND). We found that a few fundamental dynamical processes are profoundly different in MOND and in…

Astrophysics · Physics 2015-05-13 Carlo Nipoti , Pasquale Londrillo , Luca Ciotti

We consider the reasons why a cuspy NFW-like profile persistently occurs in N-body simulations, in contradiction to some astronomical observations. The routine method of testing the convergence of N-body simulations (in particular, the…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-03 Anton N. Baushev

In this fourth article on weighing the Galactic disk using the shape of the phase-space spiral, we have tested our method on a billion particle three-dimensional N-body simulation, comprised of a Milky Way like host galaxy and a merging…

Astrophysics of Galaxies · Physics 2022-07-06 Axel Widmark , Jason A. S. Hunt , Chervin F. P. Laporte , Giacomo Monari

Monte Carlo methods are widely used in particle physics to integrate and sample probability distributions (differential cross sections or decay rates) on multi-dimensional phase spaces. We present a Neural Network (NN) algorithm optimized…

High Energy Physics - Phenomenology · Physics 2020-10-21 Matthew D. Klimek , Maxim Perelstein

Dark matter N-body simulations provide a powerful tool to model the clustering of galaxies and help interpret the results of galaxy redshift surveys. However, the galaxy properties predicted from N-body simulations are not necessarily…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-30 Hao-Yi Wu , Dragan Huterer

We simulate the growth of large-scale structure in the universe using a N-body code. By combining these simulations with a Monte-Carlo method, we generate galaxy distributions at present that reproduces the observed morphology-density…

Astrophysics · Physics 2009-10-30 Hugo Martel , Premana Premadi , Richard Matzner

Chemo-dynamical N-body simulations are an essential tool for understanding the formation and evolution of galaxies. As the number of observationally determined stellar abundances continues to climb, these simulations are able to provide new…

Astrophysics of Galaxies · Physics 2016-03-23 Yves Revaz , Alexis Arnaudon , Matthew Nichols , Vivien Bonvin , Pascale Jablonka