Recent Work in Quantum Dynamics and Nuclear Physics II. Non‐Quantum Theories of the Elementary Particles

1937 ◽  
Vol 8 (11) ◽  
pp. 399-404 ◽  
Author(s):  
E. L. Hill
Keyword(s):  
Recent Work ◽  
Nuclear Physics ◽  
Quantum Dynamics ◽  
Elementary Particles ◽  
Quantum Theories

Covariant Regularization of Nonlinear Spinorfield Quantum Theories and Probability Interpretation

2000 ◽  
Vol 55 (3-4) ◽  
pp. 415-432
Author(s):  
Harald Stumpf
Keyword(s):  
State Space ◽  
Quantum Dynamics ◽  
Physical State ◽  
Canonical Quantization ◽  
Decomposition Theorem ◽  
Auxiliary Field ◽  
Indefinite Metric ◽  
Current Conservation ◽  
Quantum Theories ◽  
Effective Dynamics

Abstract By a decomposition theorem a higher order nonlinear spinorfield equation can be transformed into a set of first order nonlinear spinorfield equations, i. e. into an auxiliary field formulation which allows canonical quantization. The quantum dynamics of the auxiliary fields is expressed in algebraic Schrödinger representation and admits only unphysical state spaces with indefinite metric. Regularization of the classical theory is transferred into quantum field theory by a noninvertible map from the corresponding auxiliary field state space into an associated physical state space, the metric of which is positive definite. For the effective dynamics in the physical state space probability current conservation is proved, and for physical states which describe composite particle configurations the existence of the state space is demonstrated

scholarly journals The place of elementary particle research in the development of modern physics

1964 ◽  
Vol 278 (1374) ◽  
pp. 290-302 ◽  
Keyword(s):  
Elementary Particle ◽  
Atomic Physics ◽  
Nuclear Physics ◽  
High Energy Physics ◽  
High Energy ◽  
Elementary Particles ◽  
Atomic Nuclei ◽  
Protons And Neutrons ◽  
Modern Physics ◽  
Energy Physics

The search for elementary particles is as old as science itself. It is always the most advanced part of physics which strives for an understanding of the fundamental constituents of matter. As physics progressed, the search for elementary particles moved on from chemistry to atomic physics, and then to nuclear physics. Not much more than a decade ago it separated from nuclear physics and became a new field, dealing no longer with the structure of atomic nuclei but with the structure of the constituents of nuclei, the protons and neutrons, and also with the structure of electrons and similar particles. This field is often referred to as high-energy physics because in it beams of particles of extremely high energy are needed for most of the relevant experiments. The purpose of this article is to present a bird’s-eye view of the new aspects which elementary particle research has recently created and to show how they fit into the framework of physics of this century.

scholarly journals Yakov Borissovich Zel'Dovich, 8 March 1914 - 2 December 1987

1994 ◽  
Vol 40 ◽  
pp. 429-441 ◽  
Keyword(s):  
General Theory ◽  
Nuclear Physics ◽  
New Technology ◽  
Elementary Particles ◽  
Chemical Physics ◽  
Theory Of Relativity ◽  
General Theory Of Relativity ◽  
Chain Reactions ◽  
Princeton University ◽  
Nuclear Chain

Yakov Borissovich Zel'Dovich was an exceedingly bright star in the firmament of Soviet and world physics and astrophysics. To these fields can be added physical chemistry or, as is sometimes said, chemical physics. More specifically, mention may be made of researches in catalysis, phase transitions, hydrodynamics, combustion and detonation theory, nuclear chain reactions, nuclear physics, the theory of elementary particles and, finally, the general theory of relativity and cosmology. To mark Ya.B.’s 70th birthday, two volumes of his selected works were published under the titles: Vol. 1 Chemical Physics and Hydrodynamics (1) and Vol. II Particles, Nuclei and the Universe (2). These volumes contain a complete list of Ya.B.’s works. As far as I know, both volumes are to be published in English in 1989 by Princeton University Press. The second volume concludes with an autobiographical afterword dated 3 March 1984. Unfortunately, Ya.B. died less than four years later and, although he continued to work with his former energy, these volumes (1,2) can and will provide the basis for this obituary. Access to all Ya.B.’s existing works in English translation, accompanied by expert and often highly detailed commentaries by leading specialists, together with a long editorial article of 56 pages introducing (1), provide abundant detail and references to many of Ya.B.’s articles. Ya.B.’s life can to a first approximation be divided into four periods: 1914-30, childhood and schooldays; 1931-47, the Institute of Chemical Physics, mainly work on physicochemical problems; 1947-63, work on the creation of a new technology, nuclear physics and the theory of elementary particles; 1964-87, mainly astronomy, with emphasis on the application of the general theory of relativity and on cosmology. This chronology, taken from (1,2), will also be used here.

scholarly journals Making a Quantum Universe: Symmetry and Gravity

Universe ◽  
2020 ◽  
Vol 6 (11) ◽  
pp. 194
Author(s):  
Houri Ziaeepour
Keyword(s):  
Hilbert Space ◽  
Parameter Space ◽  
Quantum Dynamics ◽  
Degrees Of Freedom ◽  
Elementary Particles ◽  
Infinite Dimensional ◽  
Quantum Universe ◽  
Theoretical Evidence ◽  
Fundamental Forces ◽  
The Universe

So far, none of attempts to quantize gravity has led to a satisfactory model that not only describe gravity in the realm of a quantum world, but also its relation to elementary particles and other fundamental forces. Here, we outline the preliminary results for a model of quantum universe, in which gravity is fundamentally and by construction quantic. The model is based on three well motivated assumptions with compelling observational and theoretical evidence: quantum mechanics is valid at all scales; quantum systems are described by their symmetries; universe has infinite independent degrees of freedom. The last assumption means that the Hilbert space of the Universe has SU(N→∞)≅areapreservingDiff.(S2) symmetry, which is parameterized by two angular variables. We show that, in the absence of a background spacetime, this Universe is trivial and static. Nonetheless, quantum fluctuations break the symmetry and divide the Universe to subsystems. When a subsystem is singled out as reference—observer—and another as clock, two more continuous parameters arise, which can be interpreted as distance and time. We identify the classical spacetime with parameter space of the Hilbert space of the Universe. Therefore, its quantization is meaningless. In this view, the Einstein equation presents the projection of quantum dynamics in the Hilbert space into its parameter space. Finite dimensional symmetries of elementary particles emerge as a consequence of symmetry breaking when the Universe is divided to subsystems/particles, without having any implication for the infinite dimensional symmetry and its associated interaction-percived as gravity. This explains why gravity is a universal force.

Nuclear Physics and Standard Model of Elementary Particles

2021 ◽  
pp. 685-727
Author(s):  
Alexandre Obertelli ◽  
Hiroyuki Sagawa
Keyword(s):  
Standard Model ◽  
Nuclear Physics ◽  
Elementary Particles
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