Since the discovery of high Tc superconductivity, the role of electron correlation on superconductivity has been an important issue in condensed matter physics.

Since the discovery of high Tc superconductivity, the role of electron correlation on superconductivity has been an important issue in condensed matter physics.

An understanding of the effects of electronic correlations in quantum systems is one of the most challenging problems in physics, partly due to the relevance in

This book had its origins in lectures presented at EPFL, Lausanne, during two separate visits (the most recent being to IRRMA). The author is most grateful to P

Readership: Graduate students and researchers in condensed matter physics.