Cosmology has become a very active research field in the last decades thanks to the impressing improvement of our observational techniques which have led to landmark discoveries such as the accelerated expansion of the universe, and have put physicists in front of new mysteries to unveil, such as the quest after the nature of dark matter and dark energy. These notes offer an approach to cosmology, covering fundamental topics in the field: the expansion of the universe, the thermal history, the evolution of small cosmological perturbations and the anisotropies in the cosmic microwave background radiation. Some extra topics are presented in the penultimate chapter and some standard results of physics and mathematics are available in the last chapter in order to provide a self-contained treatment. These notes offer an in-depth account of the above-mentioned topics and are aimed to graduate students who want to build an expertise in cosmology.

The series of texts composing this book is based on the lectures presented during the II Jose Plinio Baptista School of Cosmology, held in Pedra Azul (Espirito Santo, Brazil) between 9 and 14 March 2014. This II JBPCosmo has been entirely devoted to the problem of understanding theoretical and observational aspects of Cosmic Background Radiation (CMB).The CMB is one of the most important phenomena in Physics and a fundamental probe of our Universe when it was only 400,000 years old. It is an extraordinary laboratory where we can learn from particle physics to cosmology; its discovery in 1965 has been a landmark event in the history of physics.The observations of the anisotropy of the cosmic microwave background radiation through the satellites COBE, WMAP and Planck provided a huge amount of data which are being analyzed in order to discover important informations regarding the composition of our universe and the process of structure formation.

The series of texts composing this book is based on the lectures presented during the II Jose Plinio Baptista School of Cosmology, held in Pedra Azul (Espirito Santo, Brazil) between 9 and 14 March 2014. This II JBPCosmo has been entirely devoted to the problem of understanding theoretical and observational aspects of Cosmic Background Radiation (CMB).The CMB is one of the most important phenomena in Physics and a fundamental probe of our Universe when it was only 400,000 years old. It is an extraordinary laboratory where we can learn from particle physics to cosmology; its discovery in 1965 has been a landmark event in the history of physics.The observations of the anisotropy of the cosmic microwave background radiation through the satellites COBE, WMAP and Planck provided a huge amount of data which are being analyzed in order to discover important informations regarding the composition of our universe and the process of structure formation.