Issue EAS Publications Series Volume 36, 2009 Dark Energy and Dark Matter: Observations, Experiments and Theories Page(s) 109 - 110 DOI 10.1051/eas/0936015 Published online 30 May 2009

Dark Energy and Dark Matter: Observations, Experiments and Theories
E. Pécontal, T. Buchert, Ph. Di Stefano and Y. Copin (eds)
EAS Publications Series, 36 (2009) 109-110
DOI: 10.1051/eas/0936015

Initial condition problem for cosmological N-body simulations

T. Tatekawa¹ and S. Mizuno<sup>2

1</sup>  Department of Physics, Ochanomizu University, 2-1-1 Otsuka, Bunkyo, Tokyo 112-8610, Japan
²  Research Center for the Early Universe (RESCEU), School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan

Published online: 30 May 2009

Abstract
For a long time, the Lagrangian linear perturbation (Zel'dovich approximation, ZA) is used for initial conditions for cosmological N-body simulations. Recently, Crocce et al. (2006) proposed the improvement of the initial conditions. They applied Lagrangian second-order perturbation (2LPT) for the initial condition. Then they calculated the Lagrangian linear perturbation and showed that 2LPT initial conditions improve the evolution of non-Gaussianity for the density fluctuation in the Universe. Here we have one question. Although 2LPT initial conditions improve the cosmological N-body simulation, is 2LPT initial conditions sufficient? To answer this question, in addition to the ZA and 2LPT, we also calculate the non-Gaussianity with the initial conditions based on third-order Lagrangian perturbation theory (3LPT). Then we show reasonable order of perturbation and redshift for the initial conditions.

© EAS, EDP Sciences 2009

What is OpenURL?