Berndt Muller - Böcker

This Advanced Study Institute (ASI) brought together two distinct ·"schools of approach" to Quantum Electrodynamics (QED) in the presence of intense, external, electromagnetic fields, in an effort to lay a joint foundation for a needed theoretical explanation of the sharp e+ e- "resonances" observed in the scattering of very heavy IOns. These (GSI/Darmstadt) experiments, whose history, latest reconfirmations, and most recent data were presented in three opening sessions (Bokemeyer, Koenig), show a smooth background of positron (e+) production, as a function of e+ kinetic energy. Superimposed upon this background are four very sharp peaks, of narrow widths (~ 30 KeV) and of clear experimental significance ('" 5 standard deviations). Most ofthese peaks correspond to sharp, essentially back-to-back electron-positron emission in the ions' center of mass. Following the approach of "supercritical" potential theory (SPT), where the total ionic charge unit Z satisfies Z > 137, it has been possible to provide a detailed and apparently correct understanding of the smooth e+ e- background; a coherent description of different facets of this approach, emphasizing the nature of the charged, supercritical vacuum, was described by the authors responsible for the invention of SPT (Greiner, Muller, Rafelski). In addition, predictions for related phenomena were outlined by other lecturers using the SPT approach (Bawin, Soff, SsJrensen).

Neural Networks presents concepts of neural-network models and techniques of parallel distributed processing in a three-step approach: - A brief overview of the neural structure of the brain and the history of neural-network modeling introduces to associative memory, preceptrons, feature-sensitive networks, learning strategies, and practical applications. - The second part covers subjects like statistical physics of spin glasses, the mean-field theory of the Hopfield model, and the "space of interactions" approach to the storage capacity of neural networks. - The final part discusses nine programs with practical demonstrations of neural-network models. The software and source code in C are on a 3 1/2" MS-DOS diskette can be run with Microsoft, Borland, Turbo-C, or compatible compilers.

L'ouvrage traite d'un concept particulièrement attractif du cours de mécanique quantique avancé, c'est à dire les symétries. Après une brève introduction aux symétries en mécanique classique, le texte s'attache à leur place en mécanique quantique, aux conséquences de la symétrie de rotation, ainsi qu'à la théorie générale des groupes de Lie. Les groupes isospin, l'hypercharge SU(3), et leurs applications sont traités avant les chapitres sur les quarks et leur charme, SU(4), ainsi que les symétries dynamiques et les frontières de la recherche en physique des particules. Ce texte unique comprend plus de 120 problèmes et exercices très détaillés et corrigés, afin d'en faire l'ouvrage de référence en la matière.

"Gauge Theory of Weak Interactions" treats the unification of electromagnetic and weak interactions and considers related phenomena. First, the Fermi theory of beta decay is presented, followed by a discussion of parity violation, clarifying the importance of symmetries. Then the concept of a spontaneously broken gauge theory is introduced, and all necessary mathematical tools are carefully developed. The "standard model" of unified electroweak interactions is thoroughly discussed including current developments. The final chapter contains an introduction to unified theories of strong and electroweak interactions. Numerous solved examples and problems make this volume uniquely suited as a text for an advanced course. This fourth edition has been carefully revised.

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 last few years there has been a rapidly increasing interest in neural modeling of brain and cognitive disorders. This multidisciplinary book presents a variety of such models in neurology, neuropsychology and psychiatry. A review of work in this area is given first. Computational models are then presented of memory impairment in Alzheimer's disease, functional brain reorganization following a stroke, patterns of neural activity in epilepsy, disruption of language processes in aphasia and acquired dyslexia, altered cognitive processes in schizophrenia and depression, and related disorders. This is the first book on this topic, with contributions from many of the leading researchers in this field.

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.