Poincare Gauge Field Theory Research Articles

Spinning and Spinning Deviation Equations for Special Types of Gauge Theories of Gravity

The problem of spinning and spin deviation equations for particles as defined by their microscopic effect has led many authors to revisit non-Riemannian geometry for being described torsion and its relation with the spin of elementary particles. We obtain a new method to detect the existence of torsion by deriving the equations of spin deviations in different classes of non-Riemannian geometries, using a modified Bazanski method. We find that translational gauge potentials and rotational gauge potentials regulate the spin deviation equation in the presence of Poincare gauge field theory of gravity.

On null tratorial torsion in vacuum quadratic poincare gauge field theory

The field equations of vacuum quadratic Poincare gauge field theory (QPGFT) are solved for purely null tratorial torsion. Expressing the contortion tensor for this case is Klambda mu nu =-2(glambda mu anu -glambda nu amu ), where amu is null, and one can prove that any solution of vacuum QPGFT, whose V4 part is also a solution of Einstein's vacuum field equations with a cosmological constant, is necessarily of algebraic type N with respect to the generalised Weyl tensor. This class of exact solutions has an expansion-free, shear-free and twist-free autoparallel repeated principal null congruence. The relationship between this class and a similar class with null axial vector torsion is also discussed.

A new class of exact solutions of the vacuum quadratic Poincar� gauge field theory

A class of algebraically special exact solutions of the vacuum quadratic Poincare gauge field theory is presented. These solutions are of type III and type N and have a nonexpanding, shear-free and twist-free geodesic repeated principal null congruence. The metric is of Kundt's class, and the torsion components are solutions of certain differential equations. The solutions have been obtained using a generalised spin coefficient formalism.

The application of spin coefficient techniques in the vacuum quadratic Poincar� gauge field theory

The vacuum field equations of the quadratic Poincare gauge field theory are expressed in the spin coefficient formalism of Newman and Penrose. These are differential identities involving curvature and torsion and, for an NP-type approach, must be combined with the NP-identities in aU4 given by Jogia and Griffiths (1980). The use of the formalism is demonstrated in the derivation of some new exact solutions.

A quadratic Lagrangian for the Poincare gauge field theory of gravity?

The author is led to a gauge field Lagrangian for the Poincare gauge field theory of gravity by exploiting a certain analogy to electrodynamics. The resulting Lagrangian is quadratic in torsion and curvature and includes a cosmological term. Moreover, the author finds the Lagrangian leading to the Klein-Gordon equation for a Dirac field in a Riemann-Cartan spacetime.

A magnetic-monopole-type solution in the Poincar� gauge field theory of gravity

In a microscopical theory of gravity the coupling of internal gauge degrees of freedom to those of space-time are studied. A magnetic-monopole-type solution for the coupledSO(3) Yang-Mills-Higgs system in a space-time with curvature and torsion is derived. The coupling constant of the Lorentz gauge bosons can be related directly to the (constant) Higgs field and to the “cosmological constant” which is induced by the quadratic curvature terms in the Lagrangian. This reveals a new interpretation of the parameters entering the general Lagrangian density of the Poincare gauge field theory (PG).

On spherically symmetric fields with dynamic torsion in gauge theories of gravitation

Within the framework of the Poincare gauge field theory of gravity, the general gravitational Lagrangian coupled to the electromagnetic field is investigated. We treat the case of a static, spherically symmetric field with space reflection invariance. The exact solutions presented will be generated by a double-duality ansatz for the curvature. The Reissner-Nordstrom metric is singled out within a class of Lagrangians admitting an asymptotically flat metric.

Spherically Symmetric and Static Fields in Linearized Gauge Theories of Gravitation

In this paper Newtonian limit in the Poincare gauge field theory of gravitation is investigated. In spherically symmetric and static cases interior and exterior solutions of the linearized field equations with gravitational source are obtained by maens of Green's function for the five Lagrangians without ghosts and tachyons. In cases of four Lagrangians, the space-time metrics outside gravitational source are the usual Schwarzschild one of the first-order, while in the case of the fifth Lagrangian the space-time metric differs from the Schwarzschild one. Under both, Newtonian and weak gravitational field approximations, the motion of a test particle without spin should therefore be different from Newton's second law. As a result of the exchanged particles of spin the deviation from Newton's second law is a Yukawa term which is attractive. A distance-dependent gravitational “constant” G(r) can be defined according to the new result. The difference between G(r) and Newton's gravitational constant is due to a nonzero component of torsion tensor, the effect of which can be tested by measuring G(r).

A charged Taub-NUT metric with torsion: A new axially symmetric solution of the poincare gauge field theory

Within the framework of the Poincaré gauge field theory, McCrea has recently discovered a Taub-NUT-like metric with torsion. The metric is axially symmetric, whereas the torsion turns out to be SO(3)-symmetric. We find the corresponding solution with an additional electric charge.

Static, vacuum, cylindrical and plane symmetric solutions of the quadratic Poincare gauge field equations

The author presents some static, cylindrical and plane symmetric solutions to the equations of the quadratic Poincare gauge field theory developed by Hehl (1979) and Baetler et al. (1980).