The contributions to this volume review the mathematical description of complex phenomena from both a deterministic and stochastic point of view. The interface between theoretical models and the understanding of complexity in engineering, physics and chemistry is explored. The reader will find information on neural networks, chemical dissipation, fractal diffusion, problems in accelerator and fusion physics, pattern formation and self-organisation, control problems in regions of insta- bility, and mathematical modeling in biology.

This volume originated in a happy event honoring Arthur Schawlow on his 65th birthday. As a research physicist, Schawlow has been a major infiuence on the present nature of physics and of high technology. He has also had a role, through the American Physical Society and other organizations, in shaping policy for the world of physicists. Important as these professional activities have been, the contributions to this volume were not prepared just for these reasons, but more for Art Schawlow the friend, colleague, and teacher. I am one who has had the privilege of knowing and collaborating with Art, probably over a longer period of time than others participating in this volume, and in a number of different enterprises; his friendship and stimulating scientific abilities are a very significant part of my own life. It is hence a pleasure to take part in this volume celebrating his contributions to science and to scientists. Schawlow's career has been geographically centered at the University of Toronto, Columbia University, the Bell Telephone Laboratories, and Stan ford University. But, as is illustrated by the papers of this volume, its effects and his personal infiuence have diffused widely. In his own work, Art Schawlow is noted for thoughtful imagination, keen physical intuition, and what might be thought an interest in gadgets - not just any gadgets, but beautiful and innovative mechanisms or new techniques in which he charac teristically recognizes important potentials.

The topics treated in this volume are intermediate and high-energy nuclear physics with real and virtual photons and the interplay between nuclear and particle physics. The first part, devoted to vector mesons, is also intended to explore the scientific perspectives of a new generation of electron accelerators. The second part is devoted to physics currently under study at intermediate-energy real-photon facilities with some emphasis on the Compton effect and its relation to quark models.

Nearly all of this book is taken from an article prepared for a volume of the Encyclopedia of Physics. This article, in turn, is partly based on Dr. Norbert Rosenzweig's translation of an older article on the same subject, written by one of us (H.A.B.) about 25 years ago for the Geiger-Scheel Handbuch der Physik. To the article written last year we have added some Addenda and Errata. These Addenda and Errata refer back to some of the 79 sections of the main text and contain some misprint corrections, additional references and some notes. The aim of this book is two-fold. First, to act as a reference work on calcu lations pertaining to hydrogen-like and helium-like atoms and their comparison with experiments. However, these calculations involve a vast array of approxi mation methods, mathematical tricks and physical pictures, which are also useful in the application of quantum mechanics to other fields. In many sections we have given more general discussions of the methods and physical ideas than is necessary for the study of the H- and He-atom alone. We hope that this book will thus at least partly fulfill its second aim, namely to be of some use to graduate students who wish to learn "applied quantum mechanics". A basic knowledge of the principles of quantum mechanics, such as given in the early chapters of Schiff's or Bohm's book, is presupposed.

Atomic cluster physics has evolved into a research field of truly interdisciplinary character. In particular, it has become apparent that phenomena in atomic nuclei have many analogues in atomic clusters. Increasing the interaction between nuclear and cluster physics can thereforeact as stimulus for both communities. The volume contains the Proceedings of a WE-Heraeus workshop on "Nuclear Physics Concepts inAtomic Cluster Physics" held in Bad Honnef (Germany), November 26-29, 1991. Both theoretical and experimental methods and results are discussed in detail, thus providing the first systematic account of the intimate connections between both fields.

The contributors to this volume study macroscopic flow properties and molecular mobility in complex liquids with high internal mobility and a highly anisotropic molecular shape. Particular attention is paid to the wide variety of experimental approaches, in theory as well as in computer simulation of these difficult but very important problems. The contributions are of interest to researchers in physics as well as in engineering and chemistry.

High-energy ion-atom collisions are subject of intense investigation in present-day atomic physics. They give fundamental information on the collision mechanism of ions and atoms, and on their highly excited states. This book includes invited survey talks, and invited contributions, all carefully refereed. The topics covered are electron capture and loss (including ionization), double electron and resonance processes, electron correlation and post-collision interaction effects, collisions of antiparticles with atoms, and so forth.

This book is devoted to the applications of the mathematical theory of solitons to physics, statistical mechanics, and molecular biology. It contains contributions on the signature and spectrum of solitons, nonlinear excitations in prebiological systems, experimental and theoretical studies on chains of hydrogen-bonded molecules, nonlinear phenomena in solid-state physics, including charge density waves, nonlinear wave propagation, defects, gap solitons, and Josephson junctions. The content is interdisciplinary in nature and displays the new trends in nonlinear physics.

Distinguished authors discuss topics in physical oceano- graphy, transonic aerodynamics, dynamics of vorticity, numerical simulation of turbulent flows, astrophysical jets, strange attractors, human-powered flight, and thefluid mechanics of the Old Faithful geyser and of the Mount St. Helens eruption of 1980. The authors deal with specific problems, but the emphasis is usually on the way that re- search is carried out at the edge of understanding, and often on the role of new techniques, instruments, and re- search strategies.

This monograph teaches advanced undergraduate students and practitioners how to use folded diagrams to calculate properties of complex particle systems such as atomic nuclei, atoms and molecules in terms of interactions among their constituents. Emphasis is on systems with valence particles in open shells. Detailed diagram rules are derived and illustrated by simple examples. Applications include nuclear optical model potentials, meson-exchange theory of the nucleon-nucleon interactions and molecular-structure problems.

The book is devoted to the modern theory and experimental manifestation of Polarization Bremsstrahlung (PB) which arises due to scattering of charged particles from various targets: atoms, nanostructures (including atomic clusters, nanoparticle in dielectric matrix, fullerens, graphene-like two-dimensional atomic structure) and in condensed matter (monocrystals, polycrystals, partially ordered crystals and amorphous matter) The present book addresses mainly researchers interested in the radiative processes during the interaction between fast particles and matter. It also will be useful for post-graduate students specializing in radiation physics and related fields.

Superfluidity and closely related to it, superconductivity are very general phenomena that can occur on vastly different energy scales. Their underlying theoretical mechanism of spontaneous symmetry breaking is even more general and applies to a multitude of physical systems.

In these lecture notes, a pedagogical introduction to the field-theory approach to superfluidity is presented. The connection to more traditional approaches, often formulated in a different language, is carefully explained in order to provide a consistent picture that is useful for students and researchers in all fields of physics.

After introducing the basic concepts, such as the two-fluid model and the Goldstone mode, selected topics of current research are addressed, such as the BCS-BEC crossover and Cooper pairing with mismatched Fermi momenta."

Ouverts a I'ensemble de la communaute internationale, les symposia ASTM-EURATOM sur la dosimetrie des rayonnements de reilcteur traitent de tous les sujets de dosimetrie dans tous les systemes a neutron: dosimetrie des experiences en reacteur, codes d'ajustement, precision, etalons et intercomparaison, donnees nucleaires, techniques de mesure, correlation de dommages radio-induits, echauffement nucleaire, etc ...appliques principalement aujourd'hui aux problemes des reacteurs a eau legere, des reacteurs a neutrons rapides et aux systemes a fusion. Les travaux en dosimetrie, tout comme I'ensemble du domaine de I'energie atomique, sont moins caracterises aujourd'hui par des idees scientifiques franchement nouvelles que par la necessite d'echange, de cooperation, de collaboration, appliques a la satisfaction de besoins de type industriel ou quasi-industriel. L'organisation de nos symposia a suivi cette evolution.Nombre de ceux qui y ont participe ont un souvenir emu du ler symposium a Petten en 1975, qui fut une reussite complete.L'organisation et Ie devouement du CCR de Petten y avait beaucoup contribue. Et puis, aussi, c'etait un commencement, c'etait Ie premier de nos symposia ...Les symposia suivants, alternativement aux USA et en EUROPE, a rythme sensiblement bi-annuel, ont du faire face progressivement a un besoin plus grand d'echange et de discussion par petits groupes, ainsi qu'a afflux croissant de propositions de communications de valeur. L'organisation a du s'adapter en consequence. Ce 5eme sy~posium ASTM- EURATOM represente, de part sa belle reussite, une etape importante de cette evolution et un garant de la maturation correspondante.

This thesis unifies the dissipative dynamics of an atom, particle or structure within an optical field that is influenced by the position of the atom, particle or structure itself. This allows the identification and exploration of the fundamental 'mirror-mediated' mechanisms of cavity-mediated cooling leading to the proposal of a range of new techniques based upon the same underlying principles. It also reveals powerful mechanisms for the enhancement of the radiation force cooling of micromechanical systems, using both active gain and the resonance of a cavity to which the cooled species are external. This work has implications for the cooling not only of weakly-scattering individual atoms, ions and molecules, but also for highly reflective optomechanical structures ranging from nanometre-scale cantilevers to the metre-sized mirrors of massive interferometers.

Nuclear reactions at energies near and below the Coulomb barrier have found much interest since unexpectedly large cross sections of fusion for heavy ions were discovered around 1980. This book covers the more important experimental and theoretical aspects such as sub-barrier fusion, sub- and near-barrier transfer, couplings of various reaction channels, neck-formation, the threshold anomaly, spin distributions and fusion of polarized ions. The symposium also included a session devoted to mass spectrometry for fast reaction products.

Semiclassical Theory of Atoms presents a novel approach to theoretical atomic physics. The fundamental quantity in this new, powerful formalism is the effective potential, not the density. The starting point is the highly semiclassical approximation known as the Thomas-Fermi model. It is studied in great detail, and then refined in three steps by adding quantum corrections successively according to their importance. First, the strongly bound electrons are treated in detail. Second, the bulk of electrons is better described by introducing quantum corrections to the Thomas-Fermi treatment and by including the exchange interaction. At this stage, predicted binding energies, for instance, are correct to within a small fraction of a percent. Third, shell effects are introduced. The improved semiclassical treatment is then sufficiently refined to reproduce the systematics of the Periodic Table. It addresses the graduate student with a good knowledge of elementary quantum mechanics.

This is a comprehensive overview of the information yielded by electroweak probes about the nuclear- and subnuclear-scale structure of matter. Lepton-induced processes from low energy through to the highest energies are considered. The first three lectures review electromagneticprocesses in hadrons; others cover the properties of partons, the behaviour of the constituents of the hadron, muon and neutrino scattering etc. An introduction to electroweak theory including the status of precision tests and data analyses is given along with a report on the first results from HERA. The lecturers have endeavoured to achieve a balance between scientific and didactic aspects thus making the book accessible also to students of nuclear and particle physics.

Experimental methods employing spin resonance effects (nuclear magnetic resonance and electron spin resonance) are broadly used in molecular science due to their unique potential to reveal mechanisms of molecular motion, structure, and interactions. The developed techniques bring together biologists investigating dynamics of proteins, material science researchers looking for better electrolytes, or nanotechnology scientists inquiring into dynamics of nano-objects. Nevertheless, one can profit from the rich source of information provided by spin resonance methods only when appropriate theoretical models are available. The obtained experimental results reflect intertwined quantum-mechanical and dynamical properties of molecular systems, and to interpret them one has to first understand the quantum-mechanical principles of the underlying processes. This book concentrates on the theory of spin resonance phenomena and the relaxation theory, which have been discussed from first principles to introduce the reader to the language of quantum mechanics used to describe the behaviour of atomic nuclei and electrons. There is a long way from knowing complex formulae to apply them correctly to describe the studied system. The book shows through examples how symbols can be "replaced" in equations by using properties of real systems to formulate descriptions that link the quantities observed in spin resonance experiments with dynamics and structure of molecules.

The present book provides an introduction to quantum optics, the study of optical effects that cannot be explained by classical theory. Its main concern is the theoretical background to the key experiments in quantum optics. More than half of the material in this third edition is new, the material that has appeared in the previous editions already has been updated. The level of the treatment as a whole is appropriate for postgraduate students and research workers, while earlier chapters are also suitable for final-year undergraduates.

Dispersion forces acting on both atoms and bodies play a key role in modern nanotechnology. As demonstrated in this book, macroscopic quantum electrodynamics provides a powerful method for understanding and quantifying dispersion forces in a vast range of realistic scenarios. The basic physical concepts and theoretical steps allow for the derivation of outlined general expressions for dispersion forces. As illustrated by a number of examples, these expressions can easily be used to study forces between objects of various shapes and materials, including effects like material absorption, nontrivial magnetic properties and dynamical forces asssociated with excited systems.

Marco Schroeter investigates the influence of the local environment on the exciton dynamics within molecular aggregates, which build, e.g., the light-harvesting complexes of plants, bacteria or algae by means of the hierarchy equations of motion (HEOM) method. He addresses the following questions in detail: How can coherent oscillations within a system of coupled molecules be interpreted? What are the changes in the quantum dynamics of the system for increasing coupling strength between electronic and nuclear degrees of freedom? To what extent does decoherence govern the energy transfer properties of molecular aggregates?.

The book is a comprehensive edition which considers the interactions of atoms, ions and molecules with charged particles, photons and laser fields and reflects the present understanding of atomic processes such as electron capture, target and projectile ionisation, photoabsorption and others occurring in most of laboratory and astrophysical plasma sources including many-photon and many-electron processes. The material consists of selected papers written by leading scientists in various fields.

Ultra-cold atomic ensembles have emerged in recent years as a powerful tool in many-body physics research, quantum information science and metrology. This thesis presents an experimental and theoretical study of the coherent properties of trapped atomic ensembles at high densities, which are essential to many of the aforementioned applications. The study focuses on how inter-particle interactions modify the ensemble coherence dynamics, and whether it is possible to extend the coherence time by means of external control. The thesis presents a theoretical model which explains the effect of elastic collision of the coherence dynamics and then reports on experiments which test this model successfully in the lab. Furthermore, the work includes the first implementation of dynamical decoupling with ultra-cold atomic ensembles. It is demonstrated experimentally that by using dynamical decoupling the coherence time can be extended 20-fold. This has a great potential to increase the usefulness of these ensembles for quantum computation.

Gauge field theories underlie all models now used in elementary particle physics. These theories refer to the class of singular theories which are also theories with constraints. The quantization of singular theories remains one of the key problems of quantum field theory and is being intensively discussed in the literature. This book is an attempt to fill the need for a comprehensive analysis of this problem, which has not heretofore been met by the available monographs and reviews. The main topics are canonical quantization and the path integral method. In addition, the Lagrangian BRST quantization is completely described, for the first time in a monograph. The book also presents a number of original results obtained by the authors, in particular, a complete description of the physical sector of an arbitrary gauge theory, quantization of singular theories with higher theories with time-dependent constraints, and correct derivatives, quantization of canonical quantization of theories of a relativistic point-like particle. As a general illustration we present quantization of field theories such as electrodynamics, Yang-Mills theory, and gravity. It should be noted that this monograph is aimed not only at giving the reader the rules of quantization according to the principle "if you do it this way, it will be good," but also at presenting strong arguments based on the modem interpretation of the classical and quantum theories which show that these methods. are the natural, if not the only possible ones."