Skewness induced by gravity

Abstract

view Abstract Citations (196) References (20) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Skewness Induced by Gravity Juszkiewicz, R. ; Bouchet, F. R. ; Colombi, S. Abstract Large-scale structures, observed today, are generally believed to have grown from random, small-amplitude inhomogeneities, present in the early universe. We investigate how gravitational instability drives the distribution of these fluctuations away from the initial state, assumed to be Gaussian. Using second-order perturbation theory, we calculate !he skewness factor, S_3_ = <δ^3^>/<δ^2^>^2^. Here the angle brackets, <...>, denote an ensemble average, and δ is the density contrast field, smoothed with a low-pass spatial filter. We show that S_3_ decreases with the slope of the fluctuation power spectrum; it depends only weakly on {OMEGA}, the cosmological density parameter. We compare perturbative calculations with N-body experiments and find excellent agreement over a wide dynamic range. If galaxies trace the mass, measurements of S3 can be used to distinguish models with Gaussian initial conditions from their non-Gaussian alternatives. Publication: The Astrophysical Journal Pub Date: July 1993 DOI: 10.1086/186927 arXiv: arXiv:astro-ph/9306003 Bibcode: 1993ApJ...412L...9J Keywords: Cosmology; Gravitational Effects; Perturbation Theory; Skewness; Galactic Clusters; Mathematical Models; Variations; Astrophysics; COSMOLOGY: LARGE-SCALE STRUCTURE OF UNIVERSE; GALAXIES: CLUSTERING; Astrophysics E-Print: 10 pages, for hardcopy with figure contact BEST@SNS.IAS.BITNET, Institute for Advanced Study number AST 92/28 full text sources arXiv | ADS |