Kurtosis and large-scale structure

Abstract:

We discuss the nonlinear growth of the excess kurtosis parameter of the smoothed density fluctuation field δ, S4 ≡ [〈δ4〉 - 3〈δ2〉2]/〈δ 2〉3 in an Einstein-de Sitter universe. We assume Gaussian primordial density fluctuations with scale-free power spectrum P(k) ∝ kn and analyze the dependence of S4 on primordial spectral index n, after smoothing with a Gaussian filter. As already known for the skewness ratio S3, the kurtosis parameter is a decreasing function of n, both in exact perturbative theory and in the Zel'dovich approximation. The parameter S4 provides a powerful statistics to test different cosmological scenarios.

Año de publicación:

1994

Keywords:

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

Fuente:

scopus