ELKO SPINOR FIELDS AS A TOOL FOR PROBING EXOTIC TOPOLOGICAL SPACETIME FEATURES

2011 ◽  
Vol 03 ◽  
pp. 133-142 ◽  
Author(s):  
ROLDÃO DA ROCHA ◽  
J. M. HOFF DA SILVA ◽  
ALEX E. BERNARDINI
Keyword(s):  
Topological Analysis ◽  
Additional Term ◽  
Dirac Spinor ◽  
Complete Evaluation ◽  
Gauge Transformations ◽  
Spinor Fields ◽  
Klein Gordon ◽  
Spacetime Metric ◽  
Cech Cohomology ◽  
Elko Spinor Fields

We report about some achievements and developments provided by the ELKO program, in particular the ones recently accomplished.1 Exotic dark spinor fields has been investigated in the context of inequivalent spin structures on arbitrary curved spacetimes, which induces an additional term on the associated Dirac operator, related to a Čech cohomology class. Exotic terms operating on standard model Dirac spinor fields are usually absorbed by gauge transformations encoded as a shift of some vector potential representing an element of the cohomology group H1(M, ℤ2). That is not the case of ELKO, once they cannot carry gauge charge. As a consequence, the ELKO program requires a complete evaluation of topological analysis. Since exotic dark spinor fields also satisfy Klein-Gordon propagators, the dynamical constraints related to the exotic term in the Dirac equation can be explicitly computed. It forthwith implies that the non-trivial topology associated to the spacetime can drastically engender — from the dynamics of dark spinor fields — constraints on the spacetime metric structure. Besides being candidates to the dark matter problem, dark spinor fields are shown to be potential candidates to probe non-trivial topologies in spacetime, as well as to explain the spacetime metric structure.

scholarly journals FROM DIRAC ACTION TO ELKO ACTION

2009 ◽  
Vol 24 (16n17) ◽  
pp. 3227-3242 ◽  
Author(s):  
J. M. HOFF DA SILVA ◽  
ROLDÃO DA ROCHA
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Natural Extension ◽  
Dirac Spinor ◽  
Spinor Fields ◽  
The Standard Model ◽  
Mass Dimension ◽  
Fermionic Fields ◽  
Elko Spinor Fields ◽  
First Time

A fundamental action, representing a mass dimension-transmuting operator between Dirac and ELKO spinor fields, is performed on the Dirac Lagrangian, in order to lead it into the ELKO Lagrangian. Such a dynamical transformation can be seen as a natural extension of the Standard Model that incorporates dark matter fields. The action of the mass dimension-transmuting operator on a Dirac spinor field, that defines and introduces such a mapping, is shown to be a composition of the Dirac operator and the nonunitary transformation that maps Dirac spinor fields into ELKO spinor fields, defined in J. Math. Phys.48, 123517 (2007). This paper gives allowance for ELKO, as a candidate to describe dark matter, to be incorporated in the Standard Model. It is intended to present for the first time, up to our knowledge, the dynamical character of a mapping between Dirac and ELKO spinor fields, transmuting the mass dimension of spin one-half fermionic fields from 3/2 to 1 and from 1 to 3/2.

scholarly journals ELKO SPINOR FIELDS: LAGRANGIANS FOR GRAVITY DERIVED FROM SUPERGRAVITY

2009 ◽  
Vol 06 (03) ◽  
pp. 461-477 ◽  
Author(s):  
ROLDÃO DA ROCHA ◽  
J. M. HOFF DA SILVA
Keyword(s):  
Spinor Field ◽  
Sufficient Conditions ◽  
Dirac Spinor ◽  
Weyl Spinor ◽  
Conjugation Operator ◽  
Spinor Fields ◽  
Mass Dimension ◽  
Majorana Spinor ◽  
Dimension One ◽  
Elko Spinor Fields

Dual-helicity eigenspinors of the charge conjugation operator (ELKO spinor fields) belong — together with Majorana spinor fields — to a wider class of spinor fields, the so-called flagpole spinor fields, corresponding to the class-(5), according to Lounesto spinor field classification based on the relations and values taken by their associated bilinear covariants. There exists only six such disjoint classes: the first three corresponding to Dirac spinor fields, and the other three respectively corresponding to flagpole, flag-dipole and Weyl spinor fields. Using the mapping from ELKO spinor fields to the three classes Dirac spinor fields, it is shown that the Einstein–Hilbert, the Einstein–Palatini, and the Holst actions can be derived from the Quadratic Spinor Lagrangian (QSL), as the prime Lagrangian for supergravity. The Holst action is related to the Ashtekar's quantum gravity formulation. To each one of these classes, there corresponds a unique kind of action for a covariant gravity theory. Furthermore we consider the necessary and sufficient conditions to map Dirac spinor fields (DSFs) to ELKO, in order to naturally extend the Standard Model to spinor fields possessing mass dimension one. As ELKO is a prime candidate to describe dark matter and can be obtained from the DSFs, via a mapping explicitly constructed that does not preserve spinor field classes, we prove that — in particular — the Einstein–Hilbert, Einstein–Palatini, and Holst actions can be derived from the QSL, as a fundamental Lagrangian for supergravity, via ELKO spinor fields. The geometric meaning of the mass dimension-transmuting operator — leading ELKO Lagrangian into the Dirac Lagrangian — is also pointed out, together with its relationship to the instanton Hopf fibration.

scholarly journals ON THE ASYMPTOTIC ANALYSIS OF THE DIRAC–MAXWELL SYSTEM IN THE NONRELATIVISTIC LIMIT

2005 ◽  
Vol 02 (01) ◽  
pp. 129-182 ◽  
Author(s):  
PHILIPPE BECHOUCHE ◽  
NORBERT J. MAUSER ◽  
SIGMUND SELBERG
Keyword(s):  
Convergence Result ◽  
Nonrelativistic Limit ◽  
Dirac Spinor ◽  
Maxwell System ◽  
Poisson System ◽  
Pauli Equation ◽  
Existence Time ◽  
Self Consistent Field ◽  
Klein Gordon ◽  
Well Posed

We study the behavior of solutions of the Dirac–Maxwell system (DM) in the nonrelativistic limit c → ∞, where c is the speed of light. DM is a nonlinear system of PDEs obtained by coupling the Dirac equation for a 4-spinor to the Maxwell equations for the self-consistent field created by the moving charge of the spinor. The limit c → ∞, sometimes also called post-Newtonian, yields a Schrödinger–Poisson system, where the spin and magnetic field no longer appear. We prove that DM is locally well-posed for H1 data (for fixed c), and that as c → ∞ the existence time grows at least as fast as log(c), provided the data are uniformly bounded in H1. Moreover, if the datum for the Dirac spinor converges in H1, then the solution of DM converges, modulo a phase correction, in C([0,T];H1) to a solution of a Schrödinger–Poisson system. Our results also apply to a mixed state formulation of DM, and give also a convergence result for the Pauli equation as the "semi-nonrelativistic" limit. The proof relies on modifications of the bilinear null form estimates of Klainerman and Machedon, and extends our previous work on the nonrelativistic limit of the Klein–Gordon–Maxwell system.

On the symmetry and conservation law classification of the de Sitter–Schwarzschild metric and the corresponding wave and Klein–Gordon equations

2020 ◽  
Vol 17 (11) ◽  
pp. 2050172
Author(s):  
Ashfaque H. Bokhari ◽  
A. H. Kara ◽  
F. D. Zaman ◽  
B. B. I. Gadjagboui
Keyword(s):  
Conservation Laws ◽  
Conservation Law ◽  
De Sitter ◽  
Killing Vectors ◽  
Schwarzschild Geometry ◽  
Klein Gordon ◽  
Spacetime Metric ◽  
Variational Symmetries ◽  
Symmetry And Conservation Law

The main purpose of this work is to focus on a discussion of Lie symmetries admitted by de Sitter–Schwarzschild spacetime metric, and the corresponding wave or Klein–Gordon equations constructed in the de Sitter–Schwarzschild geometry. The obtained symmetries are classified and the variational (Noether) conservation laws associated with these symmetries via the natural Lagrangians are obtained. In the case of the metric, we obtain additional variational ones when compared with the Killing vectors leading to additional conservation laws and for the wave and Klein–Gordon equations, the variational symmetries involve less tedious calculations as far as invariance studies are concerned.

scholarly journals Geometry, Zitterbewegung, quantization

2019 ◽  
Vol 16 (09) ◽  
pp. 1950146 ◽  
Author(s):  
Luca Fabbri
Keyword(s):  
Explicit Form ◽  
Dirac Spinor ◽  
Internal Dynamics ◽  
Spinor Fields ◽  
Field Quantization ◽  
The Way

In the most general geometric background, we study the Dirac spinor fields with particular emphasis given to the explicit form of their gauge momentum and the way in which this can be inverted so as to give the expression of the corresponding velocity; we study how Zitterbewegung affects the motion of particles, focusing on the internal dynamics involving the chiral parts; we discuss the connections to field quantization, sketching in what way anomalous terms may be gotten eventually.

Quantum numbers for Dirac spinor fields on a curved space-time

1979 ◽  
Vol 20 (2) ◽  
pp. 409-413 ◽  
Author(s):  
R. G. McLenaghan ◽  
Ph. Spindel
Keyword(s):  
Space Time ◽  
Dirac Spinor ◽  
Curved Space ◽  
Spinor Fields ◽  
Quantum Numbers

scholarly journals Classification of singular spinor fields and other mass dimension one fermions

2014 ◽  
Vol 23 (14) ◽  
pp. 1444002 ◽  
Author(s):  
R. T. Cavalcanti
Keyword(s):  
Spinor Field ◽  
General Classification ◽  
Constraint Equations ◽  
Spinor Fields ◽  
Mass Dimension ◽  
Dimension One ◽  
Elko Spinor Fields

In this paper, we investigate the constraint equations of the Lounesto spinor fields classification and show that it can be used to completely characterize all the singular classes, which can potentially accommodate further mass dimension one fermions, beyond the well known Elko spinor fields. This result can be useful for two purposes: Besides a great abridgement in the classification of a given spinor field, we provide a general form of each class of spinor fields, which can be used furthermore to search for a general classification of spinors dynamics.

scholarly journals A novel approach to quantum gravity in the presence of matter without the problem of time

2020 ◽  
Vol 35 (04) ◽  
pp. 2050015
Author(s):  
Matej Pavšič
Keyword(s):  
Wave Function ◽  
Time Derivative ◽  
Scalar Fields ◽  
The Novel ◽  
Problem Of Time ◽  
Spinor Fields ◽  
Novel Approach ◽  
Quantization Of Gravity ◽  
Klein Gordon ◽  
Quantum Counterpart

An approach to the quantization of gravity in the presence of matter is examined which starts from the classical Einstein–Hilbert action and matter approximated by “point” particles minimally coupled to the metric. Upon quantization, the Hamilton constraint assumes the form of the Schrödinger equation: it contains the usual Wheeler–DeWitt term and the term with the time derivative of the wave function. In addition, the wave function also satisfies the Klein–Gordon equation, which arises as the quantum counterpart of the constraint among particles’ momenta. Comparison of the novel approach with the usual one in which matter is represented by scalar fields is performed, and shown that those approaches do not exclude, but complement each other. In final discussion it is pointed out that the classical matter could consist of superparticles or spinning particles, described by the commuting and anticommuting Grassmann coordinates, in which case spinor fields would occur after quantization.

Gravitational interactions in the Dirac spinor fields and possible structure of local space-time of fermions

2021 ◽  
pp. 129-135
Author(s):  
V.G. Krechet ◽  
◽  
V.B. Oshurko ◽  
A.E. Baidin ◽  
◽  
...  
Keyword(s):  
General Relativity ◽  
Magnetic Moment ◽  
Spinor Field ◽  
Space Time ◽  
Spin Interaction ◽  
Internal Space ◽  
Dirac Spinor ◽  
Geometric Properties ◽  
Spinor Fields ◽  
Local Space

In the framework of general relativity, possible effects of the gravitational interactions in the Dirac spinor field are considered. It is shown that these interactions manifest locally as contact spin-spin interaction of the gravitational and spinor fields. This interaction leads to the classical rotation of particles with spin ħ /2. As a result, it leads to appearance of local internal space-time with specific geometric properties for each particle. New effect of an increase of the mass of spinor particles due to this interaction is found. Also, an explanation of the existence of a magnetic moment in Dirac spinor particles as a result of a local electro-spin-spin interaction has been proposed.

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