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Related papers: Spin half in classical general relativity

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We study the systems of scalar and spinor particles with mixing emitted by external classical sources. The particles wave functions exactly accounting for external sources are obtained directly from the Lorentz invariant wave equations in…

High Energy Physics - Phenomenology · Physics 2009-02-20 Maxim Dvornikov

While it is generally agreed that the nature of spacetime must be drastically different at the Planck scale, it has been a common practice to assume that spacetime is endowed with a full pseudo-Riemannian geometry regardless of the physical…

General Relativity and Quantum Cosmology · Physics 2011-03-29 Kaća Bradonjić

Semiclassical expansion of the Wigner function for spin-1/2 fermions having an effective spacetime-dependent mass is used to analyze spin-polarization effects. The existing framework is reformulated to obtain a differential equation…

High Energy Physics - Phenomenology · Physics 2024-01-24 Samapan Bhadury , Arpan Das , Wojciech Florkowski , Gowthama K. K. , Radoslaw Ryblewski

It is shown, that a free motion of microparticles (elementary particles) in the gravitational field is multivariant (stochastic). This multivariance is conditioned by multivariant physical space-time geometry. The physical geometry is…

General Physics · Physics 2010-02-06 Yuri A. Rylov

Within the scope of Bianchi type-I cosmological model we study the role of spinor field in the evolution of the Universe. It is found that due to the spinor affine connections the energy momentum tensor of the spinor becomes non-diagonal,…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha

There must exist a reformulation of quantum field theory which does not refer to classical time. We propose a pre-quantum, pre-spacetime theory, which is a matrix-valued Lagrangian dynamics for gravity, Yang-Mills fields, and fermions. The…

General Physics · Physics 2022-02-16 Tejinder P. Singh

A self-consistent system of interaction nonlinear spinor and scalar fields within the scope of a BI cosmological model filled with perfect fluid is considered. The role of spinor field in the evolution of the Universe is studied. It is…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha

In the field theories with twistor structure particles can be identified with (spacially bounded) caustics of null geodesic congruences defined by the twistor field. As a realization, we consider the ``algebrodynamical'' approach based on…

High Energy Physics - Theory · Physics 2007-05-23 Vladimir V. Kassandrov

An Ising-type classical statistical model is shown to describe quantum fermions. For a suitable time-evolution law for the probability distribution of the Ising-spins our model describes a quantum field theory for Dirac spinors in external…

High Energy Physics - Theory · Physics 2011-11-18 C. Wetterich

In this talk, I present a theory of quantum gravity beyond Einstein. The theory is established based on spinnic and scaling gauge symmetries by treating the gravitational force on the same footing as the electroweak and strong forces. A…

High Energy Physics - Theory · Physics 2015-11-04 Yue-Liang Wu

Within the scope of isotropic FRW cosmological model the role of nonlinear spinor field in the evolution of the Universe is studied. It is found that unlike in anisotropic cosmological models in the present case the spinor field does not…

General Relativity and Quantum Cosmology · Physics 2016-07-27 Bijan Saha

In two spatial dimensions, spin characterizes how particle states re-phase under changes of frame that leave their momentum and energy invariant. Massless particles can in principle have non-trivial spin in this sense, but all existing…

High Energy Physics - Theory · Physics 2015-06-19 Philip Schuster , Natalia Toro

The general model of an arbitrary spin massive particle in any dimensional space-time is derived on the basis of Kirillov - Kostant - Souriau approach. Keywords: spinning particles, Poincar\'e group, orbit method, constrained dynamics,…

High Energy Physics - Theory · Physics 2007-05-23 S. L. Lyakhovich , A. A. Sharapov , K. M. Shekhter

There is a deep structural link between acausal spacetimes and quantum theory. As a consequence quantum theory may resolve some "paradoxes" of time travel. Conversely, non-time-orientable spacetimes naturally give rise to electric charges…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Mark J Hadley

Gravity theory is the basis of modern cosmological models. Thirring-Feynman's tensor field approach to gravitation is an alternative to General Relativity (GR). Though Field Gravity (FG) approach is still developing subject, it opens new…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Yurij Baryshev

To incorporate quantum nonlocality into general relativity, we propose that the preparation and measurement of a quantum system are simultaneous events. To make progress in realizing this proposal, we introduce a spacetime geometry that is…

General Physics · Physics 2023-11-01 Charlie Beil

Within the scope of a static cylindrically symmetric space-time we study the behavior of a nonlinear spinor field that depends on time and radial coordinates. It is found that the presence of nontrivial non-diagonal components of the…

General Relativity and Quantum Cosmology · Physics 2022-09-21 Bijan Saha

The description of space-time in a quantum theoretical framework must be considered as a fundamental problem in physics. Most attempts start with an already given classical space-time - then the quantization is done. In contrast to this the…

Quantum Physics · Physics 2007-05-23 Holger Lyre

Quantum fields do not satisfy the pointwise energy conditions that are assumed in the original singularity theorems of Penrose and Hawking. Accordingly, semiclassical quantum gravity lies outside their scope. Although a number of…

General Relativity and Quantum Cosmology · Physics 2022-04-13 Christopher J. Fewster , Eleni-Alexandra Kontou

The quantum theory of a spatially flat Friedmann-Robertson-Walker universe with a massless scalar field as source is further investigated. The classical model is singular, and in the framework of the Arnowitt-Deser-Misner canonical…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Nivaldo A. Lemos