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N-body simulations are essential tools in physical cosmology to understand the large-scale structure (LSS) formation of the Universe. Large-scale simulations with high resolution are important for exploring the substructure of universe and…

Computational Physics · Physics 2020-10-22 Shenggan Cheng , Hao-Ran Yu , Derek Inman , Qiucheng Liao , Qiaoya Wu , James Lin

Special high-accuracy direct force summation N-body algorithms and their relevance for the simulation of the dynamical evolution of star clusters and other gravitating N-body systems in astrophysics are presented, explained and compared…

Astrophysics · Physics 2007-05-23 R. Spurzem

Newtonian N-body simulations have been employed successfully over the past decades for the simulation of the cosmological large-scale structure. Such simulations usually ignore radiation perturbations (photons and massless neutrinos) and…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-07 Julian Adamek , Jacob Brandbyge , Christian Fidler , Steen Hannestad , Cornelius Rampf , Thomas Tram

We investigate the possibility of generating initial conditions for cosmological N-body simulations by simulating a system whose correlations at thermal equilibrium approximate well those of cosmological density perturbations. The system is…

Astrophysics · Physics 2009-11-10 M. Joyce , D. Levesque , B. Marcos

We present the multi-GPU realization of the StePS (Stereographically Projected Cosmological Simulations) algorithm with MPI-OpenMP-CUDA hybrid parallelization and nearly ideal scale-out to multiple compute nodes. Our new zoom-in…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-22 Gábor Rácz , István Szapudi , László Dobos , István Csabai , Alexander S. Szalay

Particle-mesh simulations trade small-scale accuracy for speed compared to traditional, computationally expensive N-body codes in cosmological simulations. In this work, we show how a data-driven model could be used to learn an effective…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-01 Nicolas Payot , Pablo Lemos , Laurence Perreault-Levasseur , Carolina Cuesta-Lazaro , Chirag Modi , Yashar Hezaveh

In the last decades cosmological N-body dark matter simulations have enabled ab initio studies of the formation of structure in the Universe. Gravity amplified small density fluctuations generated shortly after the Big Bang, leading to the…

Instrumentation and Methods for Astrophysics · Physics 2016-11-18 Ralf Kaehler , Oliver Hahn , Tom Abel

Astrophysical Challenges which demand the solution of the one million (or more) gravitating body problem are briefly discussed for the fields of cosmology, galactic nuclei and globular star clusters. Results from the classical three-body…

Astrophysics · Physics 2016-11-23 R. Spurzem , A. Kugel

Numerical simulations of self-gravitating systems are generally based on N-body codes, which solve the equations of motion of a large number of interacting particles. This approach suffers from poor statistical sampling in regions of low…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 Giovanni Manfredi , Jean-Louis Rouet , Bruce Miller , Yui Shiozawa

Understanding the physics of large cosmological surveys down to small (nonlinear) scales will significantly improve our knowledge of the Universe. Large N-body simulations have been built to obtain predictions in the non-linear regime.…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-05 Chang Chen , Yin Li , Francisco Villaescusa-Navarro , Shirley Ho , Anthony Pullen

The gravitationally-driven evolution of cold dark matter dominates the formation of structure in the Universe over a wide range of length scales. While the longest scales can be treated by perturbation theory, a fully quantitative…

Astrophysics · Physics 2009-11-10 Katrin Heitmann , Paul M. Ricker , Michael S. Warren , Salman Habib

$N$-body simulation serves as a critical method for modeling cosmic evolution and poses a significant challenge in high-performance computing. We present CUBE2, an open-source cosmological $N$-body code emphasizing memory efficiency,…

Instrumentation and Methods for Astrophysics · Physics 2026-03-05 Hao-Ran Yu , Bing-Hang Chen , Kun Xu , Ming-Jie Sheng , Jiaxin Han , Yipeng Jing , Huahua Cui

Initial conditions for (Newtonian) cosmological N-body simulations are usually set by re-scaling the present-day power spectrum obtained from linear (relativistic) Boltzmann codes to the desired initial redshift of the simulation. This…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-28 Christian Fidler , Thomas Tram , Cornelius Rampf , Robert Crittenden , Kazuya Koyama , David Wands

We describe a new parallel N-body code for cosmological simulations. The code is based on a work- and data sharing scheme, and is implemented within the Cray Research Corporation's CRAFT programming environment. Different data distribution…

Astrophysics · Physics 2009-10-28 U. Becciani , V. Antonuccio-Delogu , A. Pagliaro

We review the recent optimizations of gravitational $N$-body kernels for running them on graphics processing units (GPUs), on single hosts and massive parallel platforms. For each of the two main $N$-body techniques, direct summation and…

Instrumentation and Methods for Astrophysics · Physics 2014-09-22 Simon Portegies Zwart , Jeroen Bédorf

On large-scales, comparable to the horizon, the observable clustering properties of galaxies are affected by various general relativistic effects. To calculate these effects one needs to consistently solve for the metric, densities and…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-21 Nora Elisa Chisari , Matias Zaldarriaga

Particle-Mesh (PM) codes are still very useful tools for testing predictions of cosmological models in cases when extra high resolution is not very important. We release for public use a cosmological PM N-body code. We provide a complete…

Astrophysics · Physics 2007-05-23 Anatoly Klypin , Jon Holtzman

We present a novel $N$-body simulation method that compactifies the infinite spatial extent of the Universe into a finite sphere with isotropic boundary conditions to follow the evolution of the large-scale structure. Our approach…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-04 Gábor Rácz , István Szapudi , István Csabai , László Dobos

Numerical simulations are a versatile tool providing insight into the complicated process of structure formation in cosmology. This process is mainly governed by gravity, which is the dominant force on large scales. To date, a century after…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-04 Julian Adamek , David Daverio , Ruth Durrer , Martin Kunz

Reconstructing the Gaussian initial conditions at the beginning of the Universe from the survey data in a forward modeling framework is a major challenge in cosmology. This requires solving a high dimensional inverse problem with an…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-28 Chirag Modi , François Lanusse , Uroš Seljak , David N. Spergel , Laurence Perreault-Levasseur