These proceedings contain some selected topics in high Tc superconductivity. The experimental data presently available on high Tc superconductivity together with some of the existing theories (BCS, bipolarons, anyons, superconductivity by quantum size effect, local pairing) are reviewed.

This book originated from a course given at the Univcrsidad Aut6noma of Madrid in the Spring of 1994 and in the Universidad Complutense of Madrid in 1995. The goal of these courses is to give the non-specialist an introduction to some old and new ideas in the field of strongly correlated systems, in particular the problems posed by the high-1~ superconducting materials. As theoretical physicists, our starting viewpoint to address the problem of strongly correlat ed ferlnion systems and related issues of modern condensed matter physics ·is the renormalization group approach applied both to quantU111 field theory and statistical physics. In recent years this has become not only a powerful tool for retrieving the essential physics of interacting systems but also a link between theoretical physics and modern condensed matter physics. Furthermore, once we have this common background for dealing with apparently different prob lems, we discuss more specific topics and even phenomenological aspects of the field. In doing so we have tried to make the exposition clear and simple, with out entering into technical details but focusing ill the fundamental physics of the phenomena under study. Therefore ,ve expect that our experience ll1ay have some value to other people entering this fascinating field. We have divided these notes into three parts and each part into chapters, which correspond roughly to one or two lectures. Part I, Chaps. 1-2 (A. H. V.

This volume contains invited and contributed papers of eminent scientists who are deeply involved in the field of strongly correlated electron systems and high-Tc superconductivity. The topics of the papers include the Hubbard model, the t-J model, the polaronic model for high-Tc superconductivity, Fermi liquid and non-Fermi liquid theory, and heavy fermion systems.

The subject of the School is on the theory and phenomenology of 'classical' superconductivity. However, the selection and treatment of the different topics is done in the perspective of the new, 'high Tc'' materials, in order to clarify what is already contained in the BCS frame, and what is not.

This Conference is designed to cover the entire field of current-carrying properties of superconductors, either metallic alloys or the new high-Tc metallic oxides. Related topics will be treated as well as the large scale applications. Topics covered include magnetization and flux behaviour, current transport and critical currents, Josephson junctions and proximity effect, microwave absorption and rf surface resistance, thermal conductivity and specific heat, Hall effect and thermoelectric power, thermal fluctuations and paraconductivity, applications of high-Tc materials.