After reviewing some basic relevant properties of stationary stochastic processes (SSP), we discuss the properties of the so-called Harrison-Zeldovich like spectra of mass density perturbations. These correlations are a fundamental feature of all current standard cosmological models. Examining them in real space we note they imply a sub-poissonian normalized variance in spheres ?M2(R) ~ R-4 lnR. In particular this latter behavior is at the limit of the most rapid decay (~ R-4) of this quantity possible for any stochastic distribution (continuous or discrete). In a simple classification of all SSP into three categories, we highlight with the name "super-homogeneous" the properties of the class to which models like this, with P(0) = 0, belong. In statistical physics language they are well described as lattice or glass-like. We illustrate their properties through two simple examples: (i) the "shuffled" lattice and the One Component Plasma at thermal equilibrium.
Real space statistical properties of standard cosmological models
Andrea Gabrielli;
2003
Abstract
After reviewing some basic relevant properties of stationary stochastic processes (SSP), we discuss the properties of the so-called Harrison-Zeldovich like spectra of mass density perturbations. These correlations are a fundamental feature of all current standard cosmological models. Examining them in real space we note they imply a sub-poissonian normalized variance in spheres ?M2(R) ~ R-4 lnR. In particular this latter behavior is at the limit of the most rapid decay (~ R-4) of this quantity possible for any stochastic distribution (continuous or discrete). In a simple classification of all SSP into three categories, we highlight with the name "super-homogeneous" the properties of the class to which models like this, with P(0) = 0, belong. In statistical physics language they are well described as lattice or glass-like. We illustrate their properties through two simple examples: (i) the "shuffled" lattice and the One Component Plasma at thermal equilibrium.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.