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Related papers: The Adaptive TreePM: An Adaptive Resolution Code f…

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Quasi-N-body simulations, such as FastPM, provide a fast way to simulate cosmological structure formation, but have yet to adequately include the effects of massive neutrinos. We present a method to include neutrino particles in FastPM,…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-15 Adrian E. Bayer , Arka Banerjee , Yu Feng

Within a cosmological context, we study the behaviour of collisionless particles in the weak field approximation to General Relativity, allowing for large gradients of the fields and relativistic velocities for the particles. We consider a…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-03 Julian Adamek , Mateja Gosenca , Shaun Hotchkiss

In this work, we extend our recently developed super-resolution (SR) model for cosmological simulations to produce fully time consistent evolving representations of the particle phase-space distribution. We employ a style-based constrained…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-13 Xiaowen Zhang , Patrick Lachance , Yueying Ni , Yin Li , Rupert A. C. Croft , Tiziana Di Matteo , Simeon Bird , Yu Feng

We demonstrate that the output of a cosmological N-body simulation can, to remarkable accuracy, be scaled to represent the growth of large-scale structure in a cosmology with parameters similar to but different from those originally…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Raul E. Angulo , Simon D. M. White

A combined N--body/SPH code is presented which benefits from the high speed of the special purpose hardware GRAPE (GRAvity PipE). Besides gravitational forces, GRAPE also returns the list of neighbours and can, therefore, be used to speed…

Astrophysics · Physics 2015-06-24 Matthias Steinmetz

We propose a computer-assisted approach to studying the effective continuum behavior of spatially discrete evolution equations. The advantage of the approach is that the "coarse model" (the continuum, effective equation) need not be…

Computational Physics · Physics 2007-05-23 J. Moeller , O. Runborg , P. G. Kevrekidis , K. Lust , I. G. Kevrekidis

Molecular simulations of the forced unfolding and refolding of biomolecules or molecular complexes allow to gain important kinetic, structural and thermodynamic information about the folding process and the underlying energy landscape. In…

Soft Condensed Matter · Physics 2021-05-26 Marco Oestereich , Jürgen Gauss , Gregor Diezemann

We present a new parallel code for computing the dynamical evolution of collisional N-body systems with up to N~10^7 particles. Our code is based on the the Henon Monte Carlo method for solving the Fokker-Planck equation, and makes…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Bharath Pattabiraman , Stefan Umbreit , Wei-Keng Liao , Alok Choudhary , Vassiliki Kalogera , Gokhan Memik , Frederic A. Rasio

CO$N$CEPT (COsmological $N$-body CodE in PyThon) is a free and open-source code for cosmological $N$-body simulations on massively parallel computers with distributed memory. Collisionless dark matter is the only implemented particle…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-28 Jeppe Dakin

Constraining neutrino mass remains an elusive challenge in modern physics. Precision measurements are expected from several upcoming cosmological probes of large-scale structure. Achieving this goal relies on an equal level of precision…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-31 J. D. Emberson , Hao-Ran Yu , Derek Inman , Tong-Jie Zhang , Ue-Li Pen , Joachim Harnois-Deraps , Shuo Yuan , Huan-Yu Teng , Hong-Ming Zhu , Xuelei Chen , Zhi-Zhong Xing

Tree codes that approximate groups of distant particles with multipole expansions are the standard way to accelerate the computation of self-gravity on particles. While momentum-conserving fast multipole methods exist, parallelisation is…

Instrumentation and Methods for Astrophysics · Physics 2026-02-06 Yann Bernard , Timothée David-Cléris , Daniel J. Price , Mike Y. M. Lau

Particle-based shape modeling (PSM) is a family of approaches that automatically quantifies shape variability across anatomical cohorts by positioning particles (pseudo landmarks) on shape surfaces in a consistent configuration. Recent…

Computer Vision and Pattern Recognition · Computer Science 2025-07-11 Hong Xu , Shireen Y. Elhabian

The formation of the large-scale structure, the evolution and distribution of galaxies, quasars, and dark matter on cosmological scales, requires numerical simulations. Differentiable simulations provide gradients of the cosmological…

Instrumentation and Methods for Astrophysics · Physics 2022-11-21 Yin Li , Libin Lu , Chirag Modi , Drew Jamieson , Yucheng Zhang , Yu Feng , Wenda Zhou , Ngai Pok Kwan , François Lanusse , Leslie Greengard

Pairwise forces between particles in cosmological N-body simulations are generally softened to avoid hard collisions. Physically, this softening corresponds to treating the particles as diffuse clouds rather than point masses. For particles…

Astrophysics · Physics 2008-04-10 Alexander Shirokov

We discuss the performance characteristics of using the modification of the tree code suggested by Barnes \citep{1990JCoPh..87..161B} in the context of the TreePM code. The optimisation involves identifying groups of particles and using…

Astrophysics · Physics 2015-05-13 Nishikanta Khandai , J. S. Bagla

Computational efficiency demands discretised, hierarchically organised, and individually adaptive time-step sizes (known as the block-step scheme) for the time integration of N-body models. However, most existing N-body codes adapt…

Instrumentation and Methods for Astrophysics · Physics 2017-09-20 Walter Dehnen

Cosmological large scale structure $N$-body simulations are computation-light, memory-heavy problems in supercomputing. The considerable amount of memory is usually dominated by an inefficient way of storing more than sufficient phase space…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-31 Hao-Ran Yu , Ue-Li Pen , Xin Wang

We introduce a new code, ECOSMOG, to run N-body simulations for a wide class of modified gravity and dynamical dark energy theories. These theories generally have one or more new dynamical degrees of freedom, the dynamics of which are…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-04 Baojiu Li , Gong-Bo Zhao , Romain Teyssier , Kazuya Koyama

In this work, we bridge standard adaptive mesh refinement and coarsening on scalable octree background meshes and robust unfitted finite element formulations for the automatic and efficient solution of large-scale nonlinear solid mechanics…

Numerical Analysis · Mathematics 2021-09-01 Santiago Badia , Manuel Caicedo , Alberto F. Martín , Javier Principe

We present a suite of cosmological N-body simulations describing the "Running Friedmann-Lema{\"i}tre-Robertson-Walker" (R-FLRW) cosmological model. This model is based on quantum field theory in a curved space-time and extends {\Lambda}CDM…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-25 Antonio Bibiano , Darren J. Croton