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Related papers: The $\texttt{Abacus}$ Cosmological $N$-body Code

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Stellar systems are broadly divided into collisional and non-collisional. The latter are large-N systems with long relaxation timescales and can be simulated disregarding two-body interactions, while either computationally expensive direct…

Astrophysics of Galaxies · Physics 2021-05-05 Pierfrancesco Di Cintio , Mario Pasquato , Hyunwoo Kim , Suk-Jin Yoon

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

Direct-summation N-body algorithms compute the gravitational interaction between stars in an exact way and have a computational complexity of O(N^2). Performance can be greatly enhanced via the use of special-purpose accelerator boards like…

Modeling of collisionless galactic systems is based on the N-body model, which requires large computational resources due to the long-range nature of gravitational forces. The most common method for calculating gravity is the TreeCode…

Computational Physics · Physics 2024-12-03 Nikolay M. Kuzmin , Danila S. Sirotin , Alexander V. Khoperskov

We discuss the cosmological simulation code GADGET-2, a new massively parallel TreeSPH code, capable of following a collisionless fluid with the N-body method, and an ideal gas by means of smoothed particle hydrodynamics (SPH). Our…

Astrophysics · Physics 2009-11-11 Volker Springel

$N$-body simulations study the dynamics of $N$ particles under the influence of mutual long-distant forces such as gravity. In practice, $N$-body codes will violate Newton's third law if they use either an approximate Poisson solver or…

Instrumentation and Methods for Astrophysics · Physics 2018-01-01 Qirong Zhu

We present a new N-body and gas dynamics code, called Nyx, for large-scale cosmological simulations. Nyx follows the temporal evolution of a system of discrete dark matter particles gravitationally coupled to an inviscid ideal fluid in an…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Ann Almgren , John Bell , Mike Lijewski , Zarija Lukić , Ethan Van Andel

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

Next generation galaxy surveys demand the development of massive ensembles of galaxy mocks to model the observables and their covariances, what is computationally prohibitive using $N$-body simulations. COLA is a novel method designed to…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-07 Albert Izard , Martin Crocce , Pablo Fosalba

As an entry for the 2012 Gordon-Bell performance prize, we report performance results of astrophysical N-body simulations of one trillion particles performed on the full system of K computer. This is the first gravitational trillion-body…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-14 Tomoaki Ishiyama , Keigo Nitadori , Junichiro Makino

Direct $N$-body simulations of star clusters are accurate but expensive, largely due to the numerous $\mathcal{O} (N^2)$ pairwise force calculations. To solve the post-million-body problem, it will be necessary to use approximate force…

Astrophysics of Galaxies · Physics 2021-08-24 Diptajyoti Mukherjee , Qirong Zhu , Hy Trac , Carl L. Rodriguez

The "gravitational million-body problem," to model the dynamical evolution of a self-gravitating, collisional N-body system with ~10^6 particles over many relaxation times, remains a major challenge in computational astrophysics.…

Instrumentation and Methods for Astrophysics · Physics 2018-12-07 Carl L. Rodriguez , Bharath Pattabiraman , Sourav Chatterjee , Alok Choudhary , Wei-keng Liao , Meagan Morscher , Frederic A. Rasio

In this study, an $N$-body simulation code was developed for self-gravitating systems with a limited first-order post-Newtonian approximation. The code was applied to a special case in which the system consists of one massive object and…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-27 Takayuki Tatekawa

We present the results of gravitational direct $N$-body simulations using the Graphics Processing Unit (GPU) on a commercial NVIDIA GeForce 8800GTX designed for gaming computers. The force evaluation of the $N$-body problem is implemented…

Astrophysics · Physics 2008-11-26 Robert G. Belleman , Jeroen Bedorf , Simon Portegies Zwart

We report on improvements made over the past two decades to our adaptive treecode N-body method (HOT). A mathematical and computational approach to the cosmological N-body problem is described, with performance and scalability measured up…

Instrumentation and Methods for Astrophysics · Physics 2013-10-18 Michael S. Warren

We give a full description of the code NBODY2 for direct integration of the gravitational N-body problem. The method of solution is based on the neighbour scheme of Ahmad & Cohen (1973) which speeds up the force calculation already for…

Astrophysics · Physics 2009-11-06 Sverre J. Aarseth

We introduce a new code for cosmological simulations, PHoToNs, which has features on performing massive cosmological simulations on heterogeneous high performance Computer (HPC) and threads oriented programming. PHoToNs adopts a hybrid…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-13 Qiao Wang , Zongyan Cao , Liang Gao , Xuebin Chi , Chen Meng , Jie Wang , Long Wang

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

This is to announce a recent release of version 1.0.1a9 of parallel load balanced adaptive P3M cosmological N-body code named GRACOS. The code has been under development over years and is available for the download at http://www.gracos.org.…

Astrophysics · Physics 2007-11-30 Alexander Shirokov

Upcoming cosmological surveys have the potential to reach groundbreaking discoveries on multiple fronts, including the neutrino mass, dark energy, and inflation. Most of the key science goals require the joint analysis of datasets from…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-12 Adrian E. Bayer , Yici Zhong , Zack Li , Joseph DeRose , Yu Feng , Jia Liu