Starting at the level of graduate students, this book offers a comprehensive introduction to a rapidly developing field of turbulence. It also presents the state of the art of the theory of wave turbulence in diverse media for researchers looking for a formalism to solve existing problems or for new research subjects and ideas. The book provides a general theory of developed wave turbulence in different media: plasmas, solids, atmosphere, oceans and space.The presentation starts with a simple and intuitive dimensional analysis and proceeds to a rigorous analytic theory with exact solutions for the stationary spectra of turbulence, stability theory of such spectra, description of nonstationary regimes and matching spectra with pumping and dissipation regions. The reader is provided with the necessary tools to study nonlinear waves and turbulence: Hamiltonian formalism, statistical description, derivation of kinetics equations and methods of finding their steady and non-steady solutions.In this second edition the book is brought up to date both in theoretical and experimental/observational aspects. In particular, the authors have updated and revised the description of nonstationary turbulence, turbulent entropy production, etc, and added discussions of master equation and several cases of strong turbulence and nonlocal cascades. The book now includes excercises, some with solutions.
