Fast generation of ensembles of cosmological N-body simulations via mode resampling

Michael D. Schneider, Shaun Cole, Carlos S. Frenk, I. Szapudi

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

We present an algorithm for quickly generating multiple realizations of N-body simulations to be used, for example, for cosmological parameter estimation from surveys of large-scale structure. Our algorithm uses a new method to resample the large-scale (Gaussian-distributed) Fourier modes in a periodic N-body simulation box in a manner that properly accounts for the nonlinear mode coupling between large and small scales. We find that our method for adding new large-scale mode realizations recovers the nonlinear power spectrum to sub-percent accuracy on scales larger than about half the Nyquist frequency of the simulation box. Using 20 N-body simulations, we obtain a power spectrum covariance matrix estimate that matches the estimator from Takahashi et al. (from 5000 simulations) with

Original languageEnglish
Article number11
JournalAstrophysical Journal
Volume737
Issue number1
DOIs
Publication statusPublished - Aug 10 2011

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simulation
boxes
power spectra
Nyquist frequencies
estimators
coupled modes
matrix
estimates
method
parameter estimation

Keywords

  • cosmological parameters
  • large-scale structure of universe
  • methods: numerical

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Fast generation of ensembles of cosmological N-body simulations via mode resampling. / Schneider, Michael D.; Cole, Shaun; Frenk, Carlos S.; Szapudi, I.

In: Astrophysical Journal, Vol. 737, No. 1, 11, 10.08.2011.

Research output: Contribution to journalArticle

Schneider, Michael D. ; Cole, Shaun ; Frenk, Carlos S. ; Szapudi, I. / Fast generation of ensembles of cosmological N-body simulations via mode resampling. In: Astrophysical Journal. 2011 ; Vol. 737, No. 1.
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