In this third volume of three, quantum electrodynamics is formulated in the language of physical „dressed" particles. A theory where charged particles interact via instantaneous action-at-a-distance forces is constructed - without need for renormalization. This theory describes electromagnetic phenomena in terms of directly interacting charges, but in full accord with fundamental principles of relativity and causality. Contents Three ways to look at QFT Dressing What are advantages of dressed Hamiltonian? Coulomb potential and beyond Decays RQD in higher orders Classical electrodynamics Experimental support of RQD Particles and relativity Special theory of relativity Unitary dressing transformation Integral for decay law Coulomb scattering integral in fourth order Relativistic invariance of Coulomb–Darwin–Breit electrodynamics

The bulk of known results in spectral and scattering theory for Schrodinger operators has been derived by time-independent (also called stationary) methods, which make extensive use of re solvent estimates and the spectral theorem. In very recent years there has been a partial shift of emphasis from the time-indepen dent to the time-dependent theory, due to the discovery of new, essentially time-dependent proofs of a fair number of the principal results such as asymptotic completeness, absence of singularly con tinuous spectrum and properties of scattering cross sections. These new time-dependent arguments are somewhat simpler than the station ary ones and at the same time considerably closer to physical in tuition, in that they are based on a rather detailed description of the time evolution of states in configUration space (whence the designation "geometric methods" used by some authors). It seemed interesting to me to present some of these new meth ods from a strictly time-dependent point of view, by considering as the basic mathematical object strongly continuous unitary one parameter groups and avoiding the spectral theorem completely. The present volume may be viewed as an essay in this spirit. It is an extended version of a course taught in 1979 at the University of Geneva to undergraduate students enrolled in mathematical physics.

This book describes a relativistic quantum theory developed by the author starting from the E.C.G. Stueckelberg approach proposed in the early 40s. In this framework a universal invariant evolution parameter (corresponding to the time originally postulated by Newton) is introduced to describe dynamical evolution. This theory is able to provide solutions for some of the fundamental problems encountered in early attempts to construct a relativistic quantum theory. A relativistically covariant construction is given for which particle spins and angular momenta can be combined through the usual rotation group Clebsch-Gordan coefficients. Solutions are defined for both the classical and quantum two body bound state and scattering problems. The recently developed quantum Lax-Phillips theory of semi group evolution of resonant states is described. The experiment of Lindner and coworkers on interference in time is discussed showing how the property of coherence in time provides a simple understanding of the results. The full gauge invariance of the Stueckelberg-Schroedinger equation results in a 5D generalization of the usual gauge theories. A description of this structure and some of its consequences for both Abelian and non-Abelian fields are discussed. A review of the basic foundations of relativistic classical and quantum statistical mechanics is also given. The Bekenstein-Sanders construction for imbedding Milgrom's theory of modified spacetime structure into general relativity as an alternative to dark matter is also studied.

This book is intended for physicists and chemists who need to understand the theory of atomic and molecular structure and processes, and who wish to apply the theory to practical problems. As far as practicable, the book provides a self-contained account of the theory of relativistic atomic and molecular structure, based on the accepted formalism of bound-state Quantum Electrodynamics. The author was elected a Fellow of the Royal Society of London in 1992.

This book presents an accessible treatment of non-relativistic and relativistic quantum mechanics. It is an ideal textbook for undergraduate and graduate physics students, and is also useful to researchers in theoretical physics, quantum mechanics, condensed matter, mathematical physics, quantum chemistry, and electronics. This student-friendly and self-contained textbook covers the typical topics in a core undergraduate program, as well as more advanced, graduate-level topics with an elegant mathematical rigor, contemporary style, and rejuvenated approach. It balances theory and worked examples, which reinforces readers' understanding of fundamental concepts. The analytical methods employed in this book describe physical situations with mathematical rigor and in-depth clarity, emphasizing the essential understanding of the subject matter without need for prior knowledge of classical mechanics, electromagnetic theory, atomic structure, or differential equations. Key Features: • Remains accessible but incorporates a rigorous, updated mathematical treatment • Laid out in a student-friendly structure • Balances theory with its application through examples Lukong Cornelius Fai is a professor of theoretical physics at the Department of Physics, Faculty of Sciences, University of Dschang, Cameroon. He is Head of Condensed Matter and Nanomaterials as well as the Mesoscopic and Multilayer Structures Laboratory. He was formerly a senior associate at the Abdus Salam International Centre for Theoretical Physics (ICTP), Italy. He holds a Master of Science in Physics and Mathematics (1991) as well as a Doctor of Science in Physics and Mathematics (1997) from Moldova State University. He is the author of over 170 scientific publications and five textbooks.

This book covers advanced topics in quantum mechanics, including nonrelativistic multi-particle systems, relativistic wave equations, and relativistic fields. Numerous examples for application help readers gain a thorough understanding of the subject. The presentation of relativistic wave equations and their symmetries, and the fundamentals of quantum field theory lay the foundations for advanced studies in solid-state physics, nuclear, and elementary particle physics. The authors earlier book, Quantum Mechanics, was praised for its unsurpassed clarity.

This book describes Relativistic Quantum Mechanics, starting from the free field equations for spin-zero particles and for spin-one-half particles, leading to the Klein-Gordon equation and Dirac equations. Interactions of these particles with the electromagnetic field through minimal coupling are introduced as well as other interactions between particles. It includes the calculation of the fundamental processes of Quantum Electrodynamics by means of Feynman's propagator theory, which allows for a proper treatment of diverse scattering and particle creation processes. In addition to this, a number of special topics are discussed, such as spontaneous symmetry breaking, the global and local cases, the Higgs mechanism, axion-photon interactions using techniques borrowed from scalar QED, pair creation in a strong external electric field, the two-dimensional representation of the Klein-Gordon propagator, bound states in the Greens functions approach, and the Breit equation for bound states. Also, the photon-electron interactions are treated in the context of a symmetric treatment within electrons and photons for eg. Compton scattering, pair creation and pair annihilation. Finally, non-abelian gauge theories, the Glashow-Weinberg-Salam model, some electroweak processes, and Feynman diagrams are also discussed.

Quantum physics and special relativity theory were two of the greatest breakthroughs in physics during the twentieth century and contributed to paradigm shifts in physics. This book combines these two discoveries to provide a complete description of the fundamentals of relativistic quantum physics, guiding the reader effortlessly from relativistic quantum mechanics to basic quantum field theory. The book gives a thorough and detailed treatment of the subject, beginning with the classification of particles, the Klein–Gordon equation and the Dirac equation. It then moves on to the canonical quantization procedure of the Klein–Gordon, Dirac and electromagnetic fields. Classical Yang–Mills theory, the LSZ formalism, perturbation theory, elementary processes in QED are introduced, and regularization, renormalization and radiative corrections are explored. With exercises scattered through the text and problems at the end of most chapters, the book is ideal for advanced undergraduate and graduate students in theoretical physics.

2012 Reprint of 1955 Edition. Exact facsimile of the original edition, not reproduced with Optical Recognition Software. Dirac is widely regarded as one of the world's greatest physicists. He was one of the founders of quantum mechanics and quantum electrodynamics. His early contributions include the modern operator calculus for quantum mechanics, which he called transformation theory, and an early version of the path integral. His relativistic wave equation for the electron was the first successful attack on the problem of relativistic quantum mechanics. Dirac founded quantum field theory with his reinterpretation of the Dirac equation as a many-body equation, which predicted the existence of antimatter and matter-antimatter annihilation. He was the first to formulate quantum electrodynamics, although he could not calculate arbitrary quantities because the short distance limit requires renormalization. Dirac discovered the magnetic monopole solutions, the first topological configuration in physics, and used them to give the modern explanation of charge quantization. He developed constrained quantization in the 1960s, identifying the general quantum rules for arbitrary classical systems. These lectures were given delivered and published during his tenure at Princeton's Institute for Advanced Study in the 1930's.

"Introduces readers to non-relativistic quantum mechanics and its mathematical methods"--