Understanding the way in which large-scale structures like galaxies form remains the most challenging problem in cosmology today. This text provides an up-to-date and pedagogical introduction to this exciting area of research. Part 1 deals with the Friedmann model the thermal history of the Universe and includes a description of observed structures in the Universe. Part 2 describes the theory of gravitational instability in both the linear and non-linear regimes. This part also includes chapters on the microwave background radiation large-scale velocity fields quasars and high redshift objects. Part 3 covers inflation cosmic strings and dark matter. Each chapter is accompanied by a comprehensive set of exercises to help the reader in self-study. The book will be of interest to research and graduate students in cosmology relativity theoretical physics astrophysics and astronomy. It is also suitable for use as a graduate textbook for introductory graduate level courses. Language: English