This book emphasizes the role that electron interactions play in the properties of condensed matter. It teaches the use of the powerful nonperturbative techniques that have become available in the last decades to discuss such topics as mixed valence systems, Kondo systems, heavy electrons, high-temp[...]
In the excitement and rapid pace of developments, writing pedagogical texts has low priority for most researchers. However, in transforming my lecture l notes into this book, I found a personal benefit: the organization of what I understand in a (hopefully simple) logical sequence. Very little in th[...]