Abstract
The recent observations of a dark matter complex (clumpy) distribution
have provided a new element to the debate on the correlations and
possible crossover to homogeneity of the visible matter. The strong
clumpiness characterizing galaxy structures seems to be present in the
overall mass distribution and its relation to the highly isotropic
Cosmic Microwave Background Radiation (CMBR) represents a fundamental
problem. In contemporary cosmological models the structures observed
today at large scales in the distribution of galaxies are explained by
the dynamical evolution of purely self-gravitating matter (dark
matter) from an initial state with low amplitude density fluctuations.
The extension of structures, the formation of power-law correlations
characterizing the strongly clustered regime and the relation between
dark and visible matter are the key problems both from an
observational
and theoretical point of view.\\
In this puzzle Statistical Physics plays an important role in various
ways:\\
1. The complete characterization of the correlations of visible and
dark matter.\\
2. The analysis of the very small anisotropies of the CMBR and
their implications
on the initial fluctuations which recall the super-homogeneous
properties
similar to plasmas and glasses.\\
3. The dynamical processes and theories for the formation of
complex structures
from a very smooth initial distribution and in a relatively
short time.\\ \\
In the next two years the complete SDSS project will provide with samples
large enough to clarify correlation properties of galaxy structures on
large scale adding new important information to this debate
together with the new observations of dark matter.\\
I discuss the use of methods and concepts of modern statistical
physics which allow one to study cosmic structures from a new
and broader point of view, focusing on the observational determination
of the extension of the power-law correlations in galaxy distributions
and on the theoretical approaches to their formation in the
framework of
many-body gravitational dynamics.
Users
Please
log in to take part in the discussion (add own reviews or comments).