Pancakes and filaments in cosmological gravitational clustering

Abstract

We consider the geometrical properties of a distribution of matter evolving under gravitational clustering. Such a distribution can be studied using standard statistical indicators such as the correlation function as well as geometrical descriptors sensitive to 'connectedness' such as percolation analysis and Minkowski functionals. Applying these methods to N-body simulations and galaxy catalogues we find that the filling factor at the percolation threshold is usually very small reflecting the fact that the Universe consists of a network of filaments and pancakes, the latter being statistically more prominent.