The book presents the fundamental physics underlying our increased understanding of the early universe, the cosmic microwave background, large scale structure formation, the dark matter problem, and the interplay between them, focusing on the cosmic microwave background. There is an emphasis on the mutual impact of fundamental physics and cosmology, both at theoretical and experimental / observational levels, within a deep and well defined programme that additionally provides a careful interdisciplinarity. Special sections cover fractals and scaling laws in astrophysics and cosmology, and high energy and neutrino astrophysics. The nature of the domain demands different approaches and points of view (either complementary or contradictory). Readers are provided with the basics of the different competitive lines of research, affording them an excellent opportunity to learn about the real state of the disciplines and increasing their critical awareness. Readership: Experimental and theoretical physicists, astrophysicists and astronomers from a variety of backgrounds. An excellent reference for the young postdoctoral scientist. Also useful for advanced undergraduate students and senior scientists.