Decoherence and the Appearance of a Classical World in Quantum Theory

When we were preparing the first edition of this book, the concept of de coherence was known only to a minority of physicists. In the meantime, a wealth of contributions has appeared in the literature - important ones as well as serious misunderstandings. The phenomenon itself is now experimen tally clearly established and theoretically well understood in principle. New fields of application, discussed in the revised book, are chaos theory, informa tion theory, quantum computers, neuroscience, primordial cosmology, some aspects of black holes and strings, and others. While the first edition arose from regular discussions between the authors, thus leading to a clear" entanglement" of their otherwise quite different chap ters, the latter have thereafter evolved more or less independently. While this may broaden the book's scope as far as applications and methods are con cerned, it may also appear confusing to the reader wherever basic assumptions and intentions differ (as they do). For this reason we have rearranged the or der of the authors: they now appear in the same order as the chapters, such that those most closely related to the "early" and most ambitious concept of decoherence are listed first. The first three authors (Joos, Zeh, Kiefer) agree with one another that decoherence (in contradistinction to the Copen hagen interpretation) allows one to eliminate primary classical concepts, thus neither relying on an axiomatic concept of observables nor on a probability interpretation of the wave function in terms of classical concepts.

1 Introduction. - 2 Basic Concepts and Their Interpretation. - 3 Decoherence Through Interaction with the Environment. - 4 Decoherence in Quantum Field Theory and Quantum Gravity. - 5 Consistent Histories and Decoherence. - 6 Superselection Rules and Symmetries. - 7 Open Quantum Systems. - 8 Stochastic Collapse Models. - 9 Related Concepts and Methods. - A1 Equation of Motion of a Mass Point. - A2 Solutions for the Equation of Motion. - A3 Elementary Properties of Composite Systems in Quantum Mechanics. - A4 Quantum Correlations. - A5 Hamiltonian Formulation of Quantum Mechanics. - A6 Galilean Symmetry of Non-Relativistic Quantum Mechanics. - A7 Stochastic Processes. - References.