Non-Gaussianity of the density distribution in accelerating universes: II. N-body simulations

We explore the possibility of putting constraints on dark energy models with the statistical property of large scale structure in the non-linear region. In particular, we investigate the w dependence of the non-Gaussianity of the smoothed density distribution generated by the non-linear dynamics. In order to follow the non-linear evolution of the density fluctuations, we apply N-body simulations based on a P³M scheme. We show that the relative difference between the non-Gaussianity of the w ≤ -0.8 model and that of the w ≤ -1.0 model is 0.67% (skewness) and 1.2% (kurtosis) for R ≤ 8h ^-1Mpc. We also calculate the corresponding quantities for R ≤ 2h^-1Mpc, 3.0% (skewness) and 4.5% (kurtosis), and the difference turns out to be greater, even though the non-linearity on this scale is so strong that the complex physical processes of galaxy formation affect the galaxy distribution. From this, we expect it to turn out that the difference can be tested by all sky galaxy surveys with the help of mock catalogues created by selection functions, which suggests that non-Gaussianity of the density distribution may potentially play an important role in extracting information on dark energy.