B. Muller – författare

The fundamental goal of physics is an understanding of the forces of nature in their simplest and most general terms. Yet there is much more involved than just a basic set of equations which eventually has to be solved when applied to specific problems. We have learned in recent years that the structure of the ground state of field theories (with which we are generally concerned) plays an equally funda­ mental role as the equations of motion themselves. Heisenberg was probably the first to recognize that the ground state, the vacuum, could acquire certain prop­ erties (quantum numbers) when he devised a theory of ferromagnetism. Since then, many more such examples are known in solid state physics, e. g. supercon­ ductivity, superfluidity, in fact all problems concerned with phase transitions of many-body systems, which are often summarized under the name synergetics. Inspired by the experimental observation that also fundamental symmetries, such as parity or chiral symmetry, may be violated in nature, it has become wide­ ly accepted that the same field theory may be based on different vacua. Practical­ ly all these different field phases have the status of more or less hypothetical models, not (yet) directly accessible to experiments. There is one magnificent ex­ ception and this is the change of the ground state (vacuum) of the electron-posi­ tron field in superstrong electric fields.

The fundamental goal of physics is an understanding of the forces of nature in their simplest and most general terms. Yet there is much more involved than just a basic set of equations which eventually has to be solved when applied to specific problems. We have learned in recent years that the structure of the ground state of field theories (with which we are generally concerned) plays an equally funda­ mental role as the equations of motion themselves. Heisenberg was probably the first to recognize that the ground state, the vacuum, could acquire certain prop­ erties (quantum numbers) when he devised a theory of ferromagnetism. Since then, many more such examples are known in solid state physics, e. g. supercon­ ductivity, superfluidity, in fact all problems concerned with phase transitions of many-body systems, which are often summarized under the name synergetics. Inspired by the experimental observation that also fundamental symmetries, such as parity or chiral symmetry, may be violated in nature, it has become wide­ ly accepted that the same field theory may be based on different vacua. Practical­ ly all these different field phases have the status of more or less hypothetical models, not (yet) directly accessible to experiments. There is one magnificent ex­ ception and this is the change of the ground state (vacuum) of the electron-posi­ tron field in superstrong electric fields.

This book describes unusual cases of cutaneous lymphomas and is of special interest for clinicians and pathologists dealing with the vexing subject of cutaneous lymphoma. In addition to the case description, it gives the clinical, histological, and in most cases also the phenotypical features and the results of molecular techniques. A commentary puts the observations into the context of cutaneous lymphomas. Related papers are cited. The book will be especially helpful in cases which do not fit into the normal spectrum of cutaneous lymphomas. Rare entities of cutaneous lymphomas are demonstrated with high-quality pictures (4-color) and a concise text in an appealing format throughout the book.

This volume contains the lectures presented at the Workshop on QCD Vacuum Structure and Its Applications, held in Paris, France, in June 1992. The structure of the vacuum state of quantum chromodynamics is one of the major unsolved problems in strong interaction physics. Although considerable progress has been made in the last decade in understanding various aspects of QCD vacuum structure, a unified picture is still elusive. This volume covers recent advances in the major fields of relevance to the problem of the QCD vacuum, such as quark confinement, chiral symmetry breaking, nonperturbative approaches, and QCD vacuum phenomenology. It provides the first comprehensive presentation of this subject, and will be valuable tool for theorists interested in nonperturbative QCD, hadronic structure, and relativistic nuclear physics.

This volume contains the lectures presented at the Workshop on QCD Vacuum Structure and Its Applications, held in Paris, France, in June 1992. The structure of the vacuum state of quantum chromodynamics is one of the major unsolved problems in strong interaction physics. Although considerable progress has been made in the last decade in understanding various aspects of QCD vacuum structure, a unified picture is still elusive. This volume covers recent advances in the major fields of relevance to the problem of the QCD vacuum, such as quark confinement, chiral symmetry breaking, nonperturbative approaches, and QCD vacuum phenomenology. It provides the first comprehensive presentation of this subject, and will be valuable tool for theorists interested in nonperturbative QCD, hadronic structure, and relativistic nuclear physics.

This book introduces a rapidly growing new research area — the study of dynamical properties of elementary fields. The methods used in this field range from algebraic topology to parallel computer programming. The main aim of this research is to understand the behavior of elementary particles and fields under extreme circumstances, first of all at high temperature and energy density generated in the largest accelerators of the world and supposed to be present in the early evolution of our Universe shortly after the Big Bang.In particular, chaos is rediscovered in a new appearance in these studies: in gauge theories the well-known divergence of initially adjacent phase space trajectories leads over into a quasi-thermal distribution of energy with a saturated average distance of different field configurations. This particular behavior is due to the compactness of the gauge group.Generally this book is divided into two main parts: the first part mainly deals with the “classical” discovery of chaos in gauge field theory while the second part presents methods and research achievements in recent years. One chapter is devoted entirely to the presentation and discussion of computational problems. The major theme, returning again and again throughout the book, is of course the phenomenon with a thousand faces — chaos itself.This book is intended to be a research book which introduces the reader to a new research field, presenting the basic new ideas in detail but just briefly touching on the problems of other related fields, like perturbative or lattice gauge theory, or dissipative chaos. The terminology of these related fields are, however, used.Exercises are also included in this book. They deepen the reader's understanding of special issues and at the same time offer more information on related problems. For the convenience of the fast reader, solutions are presented right after the problems.

The common thread of the contributions collected here is an infrared approach to pressing problems in quantum field theory. Both high and low energy physics are represented, with much emphasis on QCD (Gribov horizons, infrared models, semiclassical applications, and effective Lagrangians). Other fields of interest are thermal infrared singularities, soft Pomeron physics, eikonal scattering phenomenology and the physics of bound states.

During the week of 3–8 June 1996, approximately 83 theoretical (and 2 experimental) physicists interested in the current problems of Quantum Chromodynamics (QCD) gathered at the American University of Paris, France, to present and discuss a total of 59 papers on Collisions, Confinement, and Chaos in QCD. Each of these three subfields filled at least two half-day sessions; and another four half-day sessions were devoted to miscellaneous and interesting papers on Quantum Field Theory (QFT), and especially on the proper construction of high-energy scattering amplitudes.

During the week of 1–6 June 1998, eminent theoretical and experimental physicists interested in the most recent quantum chromodynamics research gathered at the American University of Paris, France, to present and discuss a total of 66 papers covering an extensive range of topics.

This volume contains the proceedings of the Fifth Workshop on Quantum Chromodynamics. Topics covered include: variational approximations for correlation functions in quantum field theories; the vacuum wave function in supersymmetric matrix theory; developments in cosmology; and more.