Field Theory Methods and Quantum Critical Phenomena - Fields, Strings and Critical Phenomena, p. 563-640, (ed. E. Brézin and J. Zinn-Justin, 1990)

This session of the Summer School in Theoretical Physics concentrated on the recent advances in areas of physics ranging from (super)strings to field theory and statistical mechanics. The articles contained in this volume provide a stimulating and up-to-date account of a rapidly growing subject. Discussion focussed on the many points of convergence between field theory and statistical mechanics: conformal field theory, field theory on a lattice, the study of strongly correlated electron systems, as in the Hubbard model, leading to topological Lagrangians, which are perhaps the key of the understanding of high T c superconductivity or the fractional quantum Hall effect. The critical phenomena in (1+1) dimensions, in the domain in which quantum fluctuations are strong, are described for antiferromagnetic couplings by relativistic theories in which the methods of abelian or non-abelian bosonization are particularly powerful.