Statistical Physics for Cosmic Structures The physics of scale invariant and complex systems is a novel interdisciplinary field. Its ideas allow us to look at natural phenomena in a radically new and original way eventually leading to unifying concepts independent of the detailed structure of the systems. The objective is the study of complex scale invariant and more general stochastic structures that appear both in space and time in a vast variety of natural phenomena which exhibit new types of collective behaviors and the fostering of their understanding. This book has been conceived as a methodological monograph in which the main methods of modern statistical physics for cosmological structures and density fields (galaxies Cosmic Microwave Background Radiation etc.) are presented in detail. The main purpose is to present clearly to a workable level these methods with a certain mathematical accuracy providing also some paradigmatic examples of applications. This should result in a new and more general framework for the statistical analysis of the many new data concerning the different cosmic structures which characterize the large scale Universe and for their theoretical interpretation and modeling. TOC:Introduction. Statistical Methods. Statistically Homogeneous and Isotropic Distributions. Fractals. Multifractals and Mass Distribution. Fractal Algorithms. Bibliography.