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Related papers: A Phase-Space Approach to Collisionless Stellar Sy…

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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 propose a new numerical technique for following the evolution of a self-gravitating collisionless system in general relativity. Matter is modeled as a scalar field obeying the coupled Klein-Gordon and Einstein equations. A phase space…

Astrophysics · Physics 2009-10-28 Lawrence M. Widrow

We describe a version of an algorithm for evolving self-gravitating collections of particles that should be nearly ideal for parallel architectures. Our method is derived from the ``self-consistent field'' (SCF) approach suggested…

Astrophysics · Physics 2016-08-30 Lars Hernquist , Steinn Sigurdsson , Greg L. Bryan

The objective of the work summarised here has been to exploit and extend ideas from plasma physics and accelerator dynamics to formulate a unified description of collisionless relaxation that views violent relaxation, Landau damping, and…

Astrophysics · Physics 2007-05-23 Henry E. Kandrup

We describe a technique for solving the combined collisionless Boltzmann and Poisson equations in a discretised, or lattice, phase space. The time and the positions and velocities of `particles' take on integer values, and the forces are…

Astrophysics · Physics 2015-06-24 D. Syer , S. Tremaine

We propose a method for constructing the time-dependent phase space distribution function (DF) of a collisionless system from an isolated kinematic snapshot. In general, the problem of mapping a single snapshot to a time-dependent function…

Astrophysics of Galaxies · Physics 2021-07-21 Keir Darling , Lawrence M. Widrow

We present GPU implementations of two fast force calculation methods, based on series expansions of the Poisson equation. One is the Self-Consistent Field (SCF) method, which is a Fourier-like expansion of the density field in some basis…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Yohai Meiron , Baile Li , Kelly Holley-Bockelmann , Rainer Spurzem

The one-dimensional Vlasov-Poisson system is considered and a particle method is developed to approximate solutions without compact support which tend to a fixed background of charge as $| x | \to \infty$. Such a system of equations can be…

Numerical Analysis · Mathematics 2014-01-03 Stephen Pankavich

We extend the simplex-in-cell (SIC) technique recently introduced in the context of collisionless dark matter fluids (Abel et al. 2012; Hahn et al. 2012) to the case of collisionless plasmas. The six-dimensional phase space distribution…

Computational Physics · Physics 2015-06-25 Julian Kates-Harbeck , Samuel Totorica , Jonathan Zrake , Tom Abel

Recently, we have shown how current cosmological N-body codes already follow the fine grained phase-space information of the dark matter fluid. Using a tetrahedral tesselation of the three-dimensional manifold that describes perfectly cold…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Oliver Hahn , Tom Abel , Ralf Kaehler

Charged particle beams that remain stationary while passing through a transport channel are represented by ``self-consistent'' phase space distributions. As the starting point, we assume the external focusing forces to act continuously on…

Accelerator Physics · Physics 2024-04-10 Jürgen Struckmeier , Ingo Hofmann

Self-consistent field theory (SCFT) is one of the most widely-used framework in studying the equilibrium phase behaviors of inhomogenous polymers. For liquid crystalline polymeric systems, the main numerical challenges of solving SCFT…

Numerical Analysis · Mathematics 2024-09-16 Zhijuan He , Kai Jiang , Liwei Tan , Xin Wang

The reaction-diffusion model can generate a wide variety of spatial patterns, which has been widely applied in chemistry, biology, and physics, even used to explain self-regulated pattern formation in the developing animal embryo. In this…

Numerical Analysis · Mathematics 2020-01-29 Hui Zhang , Xiaoyun Jiang , Fanhai Zeng , George Em Karniadakis

We present a scheme for numerical simulations of collisionless self-gravitating systems which directly integrates the Vlasov--Poisson equations in six-dimensional phase space. By the results from a suite of large-scale numerical…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Kohji Yoshikawa , Naoki Yoshida , Masayuki Umemura

We present a method for solving the two-dimensional linearized collisionless Boltzmann equation using Fourier expansion along the orbits. It resembles very much solutions present in the literature, but it differs by the fact that everything…

Astrophysics · Physics 2007-05-23 P. Vauterin , H. Dejonghe

We have invented a new algorithm to use with self-gravitating SPH Star Formation codes. The new method is designed to enable SPH simulations to self-regulate their numerical resolution, i.e. the number of SPH particles; the latter is…

Astrophysics · Physics 2007-05-23 Spyridon Kitsionas

In the mean field limit, isolated gravitational systems often evolve towards a steady state through a violent relaxation phase. One question is to understand the nature of this relaxation phase, in particular the role of radial…

Astrophysics of Galaxies · Physics 2018-12-19 Anaelle Halle , Stephane Colombi , Sebastien Peirani

N-body simulations are essential for understanding the formation and evolution of structure in the Universe. However, the discrete nature of these simulations affects their accuracy when modelling collisionless systems. We introduce a new…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-18 Oliver Hahn , Raul E. Angulo

We propose a new method for generating equilibrium models of spherical systems of collisionless particles that are finite in extent, but whose central regions resemble dark matter halos from cosmological simulations. This method involves…

Astrophysics of Galaxies · Physics 2017-03-24 Nicole E. Drakos , James E. Taylor , Andrew J. Benson

We introduce a Phase Field Crystal (PFC) model for particles with n-fold rotational symmetry in two dimensions. Our approach is based on a free energy functional that depends on the reduced one-particle density, the strength of the…

Soft Condensed Matter · Physics 2023-02-02 Robert F. B. Weigel , Michael Schmiedeberg
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