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Title: Expansion techniques for collisionless stellar dynamical simulations

We present graphics processing unit (GPU) implementations of two fast force calculation methods based on series expansions of the Poisson equation. One method is the self-consistent field (SCF) method, which is a Fourier-like expansion of the density field in some basis set; the other method is the multipole expansion (MEX) method, which is a Taylor-like expansion of the Green's function. MEX, which has been advocated in the past, has not gained as much popularity as SCF. Both are particle-field methods and optimized for collisionless galactic dynamics, but while SCF is a 'pure' expansion, MEX is an expansion in just the angular part; thus, MEX is capable of capturing radial structure easily, while SCF needs a large number of radial terms. We show that despite the expansion bias, these methods are more accurate than direct techniques for the same number of particles. The performance of our GPU code, which we call ETICS, is profiled and compared to a CPU implementation. On the tested GPU hardware, a full force calculation for one million particles took ∼0.1 s (depending on expansion cutoff), making simulations with as many as 10{sup 8} particles fast for a comparatively small number of nodes.
Authors:
 [1] ; ;  [2] ;  [3]
  1. Kavli Institute for Astronomy and Astrophysics at Peking University, Beijing 100871 (China)
  2. Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States)
  3. National Astronomical Observatories of China, Chinese Academy of Sciences, Beijing 100012 (China)
Publication Date:
OSTI Identifier:
22365130
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 792; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CALCULATION METHODS; CAPTURE; COMPARATIVE EVALUATIONS; DENSITY; EXPANSION; GREEN FUNCTION; IMPLEMENTATION; PERFORMANCE; POISSON EQUATION; SELF-CONSISTENT FIELD; SIMULATION; STARS