Kurtosis as a non-Gaussian signature of the large-scale velocity field

Abstract:

We discuss the nonlinear growth of the kurtosis of the smoothed peculiar velocity field (along an arbitrary direction) in an Einstein-de Sitter universe, induced by Gaussian primordial density fluctuations. Applying the perturbative theory, we show that, for different cosmological models, a departure from the original Gaussian distribution is gravitationally induced only on scales smaller than 20-30 Mpc. Models with scale-free power spectrum P(k) ∝ kn, with -1 < n ≤ 1, are also considered. A new statistics, independent of the power spectrum normalization and of time, is introduced to measure the kurtosis of the velocity field.

Año de publicación:

1994

Keywords:

• Cosmology: theory
• Galaxies: clustering
• Large-scale structure of universe

Fuente:

scopus