FRACTALS AND THE DISTRIBUTION OF GALAXIES

This paper presents a, review of the fractal approach for describing t he large scale distribution of galaxies, We start by presenting a brie f, but general, introduction to fractals, which emphasizes their empir ical side and applications rather than their mathematical side. Then T hen discuss the standard correlation function analysis of galaxy catal ogues and many observational facts that brought increasing: doubts abo ut the reliability of this method, paying special attention to the sta ndard implicit assumption of an eventual homogeneity of the distributi on of galaxies. Some new statistical concepts for analysing this distr ibution are Presented. Without the implicit assumption of homogeneity they bring support, to the hypothesis that the distribution of galaxie s does from a fractal system. The Pietronero-Wertz's single fractal (h ierarchical) model is presented and discussed, together with the impli cations of this new approach for understanding galaxy clustering.