According to recent observations, the existence of dark energy has been considered. Even though we have obtained the constraint of the equation of the state for dark energy (p ≤ wρ) as -1 ≤ w ≤ -0.78 by combining WMAP data with other astronomical data, in order to pin down w, it is necessary to use other independent observational tools. For this purpose, we consider the w dependence of the non-Gaussianity of the density distribution generated by nonlinear dynamics. To extract the non-Gaussianity, we follow a semi-analytic approach based on Lagrangian linear perturbation theory, which provides an accurate value for the quasi-nonlinear region. From our results, the difference of the non-Gaussianity between w ≤ -1 and -0.5 is about 4%, while that between w ≤ -1 and -0.8 is about 0.9%. For the highly non-linear region, we estimate the difference by combining this perturbative approach with N-body simulation executed for our previous paper. From this, we can expect the difference to be more enhanced in the low-z region, which suggests that the non-Gaussianity of the density distribution potentially plays an important role for extracting information on dark energy.
- Cosmic flows
- Cosmological perturbation theory
- Dark energy theory
ASJC Scopus subject areas
- Physics and Astronomy(all)