An alternative to grids and glasses : Quaquaversal pre-initial conditions for N-body simulations

Summary, in English

N-body simulations sample their initial conditions on an initial particle distribution, which for cosmological simulations is usually a glass or grid, while a Poisson distribution is used for galaxy models, spherical collapse, etc. These pre-initial conditions have inherent correlations, noise due to discreteness, and preferential alignments, while the glass distribution is poorly defined and computationally expensive to construct. We present a novel particle distribution that can be useful as a pre-initial condition for N-body simulations, using a simple construction based on a "quaquaversal" tiling of space. This distribution has little preferred orientation (i.e., is statistically isotropic), has a rapidly vanishing large-scale power spectrum [P(k) ∼ k⁴], and is trivial to create. It should be particularly useful for warm dark matter and cold collapse simulations.

• Author: Steen H. Hansen; Oscar Agertz; Michael Joyce; Joachim Stadel; Ben Moore; Doug Potter
• Publishing year: 2007-02-20
• Language: English
• Pages: 631-635
• Publication/Series: Astrophysical Journal
• Volume: 656
• Issue: 2 I
• Links: http://dx.doi.org/10.1086/510477
• Document type: Journal article
• Publisher: American Astronomical Society
• Keywords: Methods: N-body simulations
• Status: Published
• ISBN/ISSN/Other: ISSN: 0004-637X