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.Comment: 42 pages, 12 figures, extended version of lectures given at the XIth
Brazilian School of Cosmology and Gravitation, Rio de Janeiro, July 26 -
August 4, 2004, prepared for AIP conference proceeding