Quantum Theory And Symmetries Iv

Symmetries in Quantum Mechanics: From Angular Momentum to Supersymmetry (PBK) provides a thorough, didactic exposition of the role of symmetry, particularly rotational symmetry, in quantum mechanics. The bulk of the book covers the description of rotations (geometrically and group-theoretically) and their representations, and the quantum theory of angular momentum. Later chapters introduce more advanced topics such as relativistic theory, supersymmetry, anyons, fractional spin, and statistics. With clear, in-depth explanations, the book is ideal for use as a course text for postgraduate and advanced undergraduate students in physics and those specializing in theoretical physics. It is also useful for researchers looking for an accessible introduction to this important area of quantum theory.

This book is the first volume of proceedings from the joint conference X International Symposium “Quantum Theory and Symmetries” (QTS-X) and XII International Workshop “Lie Theory and Its Applications in Physics” (LT-XII), held on 19–25 June 2017 in Varna, Bulgaria. The QTS series was founded on the core principle that symmetries underlie all descriptions of quantum systems. It has since evolved into a symposium at the forefront of theoretical and mathematical physics. The LT series covers the whole field of Lie theory in its widest sense, together with its applications in many areas of physics. As an interface between mathematics and physics, the workshop serves as a meeting place for mathematicians and theoretical and mathematical physicists. In dividing the material between the two volumes, the Editor has sought to select papers that are more oriented toward mathematics for the first volume, and those focusing more on physics for the second. However, this division is relative, since many papers are equally suitable for either volume. The topics addressed in this volume represent the latest trends in the fields covered by the joint conferences: representation theory, integrability, entanglement, quantum groups, number theory, conformal geometry, quantum affine superalgebras, noncommutative geometry. Further, they present various mathematical results: on minuscule modules, symmetry breaking operators, Kashiwara crystals, meta-conformal invariance, the superintegrable Zernike system.

The first version of quantum theory, developed in the mid 1920's, is what is called nonrelativistic quantum theory; it is based on a form of relativity which, in a previous volume, was called Newton relativity. But quickly after this first development, it was realized that, in order to account for high energy phenomena such as particle creation, it was necessary to develop a quantum theory based on Einstein relativity. This in turn led to the development of relativistic quantum field theory, which is an intrinsically many-body theory. But this is not the only possibility for a relativistic quantum theory. In this book we take the point of view of a particle theory, based on the irreducible representations of the Poincare group, the group that expresses the symmetry of Einstein relativity. There are several ways of formulating such a theory; we develop what is called relativistic point form quantum mechanics, which, unlike quantum field theory, deals with a fixed number of particles in a relativistically invariant way. A central issue in any relativistic quantum theory is how to introduce interactions without spoiling relativistic invariance. We show that interactions can be incorporated in a mass operator, in such a way that relativistic invariance is maintained. Surprisingly for a relativistic theory, such a construction allows for instantaneous interactions; in addition, dynamical particle exchange and particle production can be included in a multichannel formulation of the mass operator. For systems of more than two particles, however, straightforward application of such a construction leads to the undesirable property that clusters of widely separated particles continue to interact with one another, even if the interactions between the individual particles are of short range. A significant part of this volume deals with the solution of this problem. Since relativistic quantum mechanics is not as well-known as relativistic quantum field theory, a chapter is devoted to applications of point form quantum mechanics to nuclear physics; in particular we show how constituent quark models can be used to derive electromagnetic and other properties of hadrons.

This book presents the up-to-date status of quantum theory and the outlook for its development in the 21st century. The covered topics include basic problems of quantum physics, with emphasis on the foundations of quantum theory, quantum computing and control, quantum optics, coherent states and Wigner functions, as well as on methods of quantum physics based on Lie groups and algebras, quantum groups and noncommutative geometry. Contents:The Interacting Fock Space of Haldane's Exclusion Statistics (L Accardi & M Nhani)Complex Hamiltonians Having Real Spectra (C M Bender)From Rsonances to Poincaré Semigroups (A R Bohm et al.)Quantum Field Theory as Dynamical System (H J Borchers)Beta-lattices for Aperiodic Order (J-P Gazeau)Generalized Symmetries and Time (M Heller)Integrable Hierarchies and the WDVV-equations (G F Helminck)Global Gauss Law for Lattice QCD (J Kijowski & G Rudolph)Quantum Entanglement and Symmetries (M Kus)From Noncommutative Space-time to Quantum Relativistic Symmetries with Fundamental Mass Parameter (J Lukierski)Tomographic Map within the Framework of Star-product Quantization (O V Man'ko et al.)Algorithmic Cooling and Scalable Quantum Computers: Ways to Improve the Space-time Requirements of the Algorithm (T Mor & Y Weinstein)Quantum Theory on the Torus with Magnetic Field (H Narnhofer)Nonlocal Reflection by Photonic Barriers (G Nimtz & A Haibel)Lightfront Formalism versus Holography & Chiral Scanning (B Schroer)Broken Symmetries (W Thirring)Guage Theories on Non-communtative Spaces (J Wess) Readership: Researchers, lecturers and graduate students in theoretical, mathematical and quantum physics. Keywords:

This book presents the up-to-date status of quantum theory and the outlook for its development in the 21st century. The covered topics include basic problems of quantum physics, with emphasis on the foundations of quantum theory, quantum computing and control, quantum optics, coherent states and Wigner functions, as well as on methods of quantum physics based on Lie groups and algebras, quantum groups and noncommutative geometry.

This book shows that with minimal modifications of postulates of non-relativistic quantum mechanics to allow for non-unitary representations of symmetry groups (Lorentz group in particular), one achieves a fully relativistic quantum theory without any of the issues (like negative energies, etc.) that led to the second quantization and QFT. It is shown that quite a few phenomena in elementary particle physics (like for example neutral kaon mixing, CP symmetry and it's supposed breaking) can be explained purely as a consequence of relativistic invariance and relativistic invariance alone. It is shown that by categorizing mesons via the representation of Lorentz group they belong to, one can explain a lot of their properties, as well as a lot of discrepancies in the particle data tables. It is also shown that based on properties of Lorentz representations of products of meson decays, a lot of excited states listed in PDG tables are really several different excitations with similar masses. Relativistic treatment of bound states in momentum space is developed and used to calculate decay widths of various composite particles like Positronium or mesons, and then those decay widths are used to calculate various properties of quarks (like their masses or charges) that were previously misunderstood. In particular, it is shown that quarks are actually quite heavy (around 3.5GeV for up/down quarks) and that while Lorentz invariance allows both fractional values (2/3, -1/3) as well as integer values (2,1), based on (very sparse) available experimental data, integer quark charges are more consistent with observed decay widths than fractional charges.