How can fundamental particles exist as waves in the vacuum? How can such waves have particle properties such as inertia? What is behind the notion of “virtual” particles? Why and how do particles exert forces on one another? Not least: What are forces anyway? These are some of the central questions that have intriguing answers in Quantum Field Theory and the Standard Model of Particle Physics. Unfortunately, these theories are highly mathematical, so that most people - even many scientists - are not able to fully grasp their meaning. This book unravels these theories in a conceptual manner, using more than 180 figures and extensive explanations and will provide the nonspecialist with great insights that are not to be found in the popular science literature.

This is an introductory book on elementary particles and their interactions. It starts out with many-body Schrödinger theory and second quantization and leads, via its generalization, to relativistic fields of various spins and to gravity. The text begins with the best known quantum field theory so far, the quantum electrodynamics of photon and electrons (QED). It continues by developing the theory of strong interactions between the elementary constituents of matter (quarks). This is possible due to the property called asymptotic freedom. On the way one has to tackle the problem of removing various infinities by renormalization. The divergent sums of infinitely many diagrams are performed with the renormalization group or by variational perturbation theory (VPT). The latter is an outcome of the Feynman-Kleinert variational approach to path integrals discussed in two earlier books of the author, one representing a comprehensive treatise on path integrals, the other dealing with critial phenomena. Unlike ordinary perturbation theory, VPT produces uniformly convergent series which are valid from weak to strong couplings, where they describe critical phenomena.The present book develops the theory of effective actions which allow to treat quantum phenomena with classical formalism. For example, it derives the observed anomalous power laws of strongly interacting theories from an extremum of the action. Their fluctuations are not based on Gaussian distributions, as in the perturbative treatment of quantum field theories, or in asymptotically-free theories, but on deviations from the average which are much larger and which obey power-like distributions.Exactly solvable models are discussed and their physical properties are compared with those derived from general methods. In the last chapter we discuss the problem of quantizing the classical theory of gravity.

A complete explanation of quantum mechanics, from its early non-relativistic formulation to the complex field theories used so extensively in modern theoretical research, this volume assumes no specialized knowledge of the subject. It stresses relativistic quantum mechanics, since this subject plays such an important role in research, explaining the principles clearly and imparting an accurate understanding of abstract concepts. This text deals with quantum mechanics from its earliest developments, covering both the quantum mechanics of wave fields and the older quantum theory of particles. The final chapter culminates with the author's presentation of his revolutionary theory of fundamental length--a concept designed to meet many of quantum theory's longstanding basic difficulties.

Choice Outstanding Title, September 2020 This book fills a gap in the middle ground between quantum mechanics of a single electron to the concept of a quantum field. In doing so, the book is divided into two parts; the first provides the necessary background to quantum theory extending from Planck’s formulation of black body radiation to Schrodinger’s equation; and the second part explores Dirac’s relativistic electron to quantum fields, finishing with an description of Feynman diagrams and their meaning. Much more than a popular account, yet not too heavy so as to be inaccessible, this book assumes no prior knowledge of quantum physics or field theory and provides the necessary foundations for readers to then progress to more advanced texts on quantum field theory. It will be of interest to undergraduate students in physics and mathematics, in addition to an interested, general audience. Features: Provides an extensive yet accessible background to the concepts Contains numerous, illustrative diagrams Presents in-depth explanations of difficult subjects

Comprehensive graduate-level text by a distinguished theoretical physicist reveals the classical underpinnings of modern quantum field theory. Topics include space-time, Lorentz transformations, conservation laws, equations of motion, Green’s functions, and more. 1964 edition.

Teil 1: Basic properties of particles and fields. Teil 2: Basic principles and applications of differential geometry

This book provides an introduction to the current state of our knowledge about the structure of matter. Gerhard Ecker describes the development of modern physics from the beginning of the quantum age to the standard model of particle physics, the fundamental theory of interactions of the microcosm. The focus lies on the most important discoveries and developments, e.g. of quantum field theory, gauge theories and the future of particle physics. The author also emphasizes the interplay between theory and experiment, which helps us to explore the deepest mysteries of nature. "Particles, Fields, Quanta" is written for everyone who enjoys physics. It offers high school graduates and students of physics in the first semesters an encouragement to understand physics more deeply. Teachers and others interested in physics will find useful insights into the world of particle physics. For advanced students, the book can serve as a comprehensive preparation for lectures on particle physics and quantum field theory. A brief outline of the mathematical structures, an index of persons with research focuses and a glossary for quick reference of important terms such as gauge theory, spin and symmetry complete the book. From the foreword by Michael Springer: “The great successes and the many open questions this book describes illustrate how immensely complicated nature is and nevertheless how much we already understand of it.” The author Gerhard Ecker studied theoretical physics with Walter Thirring at the University of Vienna. His research focus has been on theoretical particle physics, in particular during several long-term visits at CERN, the European Organisation for Nuclear Research in Geneva. In 1986 he was promoted to Professor of Theoretical Physics at the University of Vienna. Since 1977 he has given both basic lectures in theoretical physics and advanced courses on different topics in particle physics, e.g., quantum field theory, symmetry groups in particle physics and renormalisation in quantum field theory.

The new edition provided the opportunity of adding a new chapter entitled "Principles and Lessons of Quantum Physics". It was a tempting challenge to try to sharpen the points at issue in the long lasting debate on the Copenhagen Spirit, to assess the significance of various arguments from our present vantage point, seventy years after the advent of quantum theory, where, after ali, some problems appear in a different light. It includes a section on the assumptions leading to the specific mathematical formalism of quantum theory and a section entitled "The evolutionary picture" describing my personal conclusions. Alto gether the discussion suggests that the conventional language is too narrow and that neither the mathematical nor the conceptual structure are built for eter nity. Future theories will demand radical changes though not in the direction of a return to determinism. Essential lessons taught by Bohr will persist. This chapter is essentially self-contained. Some new material has been added in the last chapter. It concerns the char acterization of specific theories within the general frame and recent progress in quantum field theory on curved space-time manifolds. A few pages on renor malization have been added in Chapter II and some effort has been invested in the search for mistakes and unclear passages in the first edition. The central objective of the book, expressed in the title "Local Quantum Physics", is the synthesis between special relativity and quantum theory to gether with a few other principles of general nature.

This volume is intended as a systematic introduction to gauge field theory for advanced undergraduate and graduate students in high energy physics. The discussion is restricted to the classical (non-quantum) theory in Minkowski spacetime. Particular attention has been given to conceptual aspects of field theory, accurate definitions of basic physical notions, and thorough analysis of exact solutions to the equations of motion for interacting systems.

First Published in 2018. The emphasis of the book is calculational, and most computations are presented in step-by-step detail. The book is unique in that it develops all three representations of quantum field theory (operator, functional Schr dinger, and path integral) for point particles and strings. In many cases, identical results are worked out in each representation to emphasize the representation-independent structures of quantum field theory