Non-Gaussianity of the density distribution in accelerating universes

Takayuki Tatekawa, Shuntaro Mizuno

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

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.

Original languageEnglish
Article number006
JournalJournal of Cosmology and Astroparticle Physics
Issue number2
DOIs
Publication statusPublished - 2006 Feb 1

Keywords

  • Cosmic flows
  • Cosmological perturbation theory
  • Dark energy theory

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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