Lectures on Astroparticle Physics

These are extended notes of a series of lectures given at the XIth Brazilian School of Cosmology and Gravitation. They provide a selection of topics at the intersection of particle and astrophysics. The first part gives a short introduction to the theory of electroweak interactions, with specific emphasize on neutrinos. In the second part we apply this framework to selected topics in astrophysics and cosmology, namely neutrino oscillations, neutrino hot dark dark matter, and big bang nucleosynthesis. The last part is devoted to ultra high energy cosmic rays and neutrinos where again particle physics aspects are emphasized. The often complementary role of laboratory experiments is also discussed in several examples.