In this book the author extends the concepts introduced in his Quantum
Field Theory in Condensed Matter Physics to situations in which the
strong electronic correlations are crucial for the understanding of the
observed phenomena. Starting from a model field theory to illustrate the
basic ideas, more complex systems are analyzed in turn. A special
chapter is devoted to the description of antiferromagnets, doped Mott
insulators, and quantum Hall liquids from the point of view of gauge
theory.