The decade 1963-1973 is sometimes referred to as the 'golden age' of black hole research. Mathematical theorems proved in this period led to a complete classical description of equilibrium black holes in four space-time dimensions. More recently, string theory has forced us to take seriously the possibility of extra spatial dimensions. Thinking about black holes in more than four dimensions has led to spectacular advances in our understanding of quantum gravity. In the last five years, we have learned that higher-dimensional black holes exhibit much richer behaviour than four-dimensional ones, even classically. I shall review the discoveries of this new 'silver age' of black hole research. The talk should be accessible to MSc students.

Within supersymmetric grand unified theories, cosmic strings are generically formed at the end of a hybrid inflationary era. However, cosmic microwave background measurements imply severe constraints on the allowed cosmic strings contribution to the temperature anisotropies. In the framework of supersymmetry, I will study F- and D-term inflation and I will set constraints on the free parameters (mass scales and couplings) of the models, so that there is compatibility between mixed models (inflation + cosmic strings) and current measurements. Recently there is a revival in interest for cosmic strings, since ina ddition, superstrings could play the role of cosmic strings in theories with large extra dimensions and moreover it may be that cosmic strings have been already seen in the sky.

Within supersymmetric grand unified theories, cosmic strings are generically formed at the end of a hybrid inflationary era. However, cosmic microwave background measurements imply severe constraints on the allowed cosmic strings contribution to the temperature anisotropies. In the framework of supersymmetry, I will study F- and D-term inflation and I will set constraints on the free parameters (mass scales and couplings) of the models, so that there is compatibility between mixed models (inflation + cosmic strings) and current measurements. Recently there is a revival in interest for cosmic strings, since ina ddition, superstrings could play the role of cosmic strings in theories with large extra dimensions and moreover it may be that cosmic strings have been already seen in the sky.