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M. I. Wanas

Publications and source records attributed to M. I. Wanas.

43 records · Page 3Linked to original sources

Quantum Features of Non-Symmetric Geometries

Paths in an appropriate geometry are usually used as trajectories of test particles in geometric theories of gravity. It is shown that non-symmetric geometries possess some interesting quantum features. Without carrying out any quantization schemes, paths in such geometries are naturally quantized. Two different non-symmetric geometries are examined for these features. It is proved that, whatever the non-symmetric geometry is, we always get the same quantum features. It is shown that these features appear only in the pure torsion term (the anti-symmetric part of the affine connection) of the path equations. The vanishing of the torsion leads to the disappearance of these features, regardless of the symmetric part of the connection. It is suggested that, in order to be consistent with the results of experiments and observations, torsion term in path equations should be parametrized using an appropriate parameter.

gr-qc↗

Motion of Spinning Particles in Gravitational Fields

A new path equation in absolute parallelism (AP) geometry is derived. The equation is a generalization of three path equations derived in a previous work. It can be considered as a geodesic equation modified by a torsion term, whose numerical coefficient jumps by steps of one half. The torsion term is parametrized using the fine structure constant. It is suggested that the new equation may describe the trajectories of spinning particles under the influence of a gravitational field, and the torsion term represents a type of interaction between the quantum spin of the moving particle and the background field. Weak field limits of the new path equation show that the gravitational potential felt by a spinning particle is different from that felt by a spinless particle (or a macroscopic body). As a byproduct, and in order to derive the new path equation, the AP-space is reconstructed using a new affine connexion preserving metricity. The new AP-structure has non-vanishing curvature. In certain limits, the new AP-structure can be reduced either to the ordinary Riemannian space, or to the conventional AP-space.

gr-qc↗

Hamilton's principle and the Generalized Field Theory : A comparative study

The field equations of the generalized field theory (GFT) are derived from an action principle. A comparison between (GFT), Møller's tetrad theory of gravitation (MTT), and general relativity is carried out regarding the Lagrangian of each theory. The results of solutions of the field equations, of each theory, are compared in case of spherical symmetry. The differences between the results are discussed and interpreted.

gr-qc↗

Quantum Interference of Thermal Neutrons and Spin-Torsion Interaction

The discrepancy of $0.8 %$ between theory and the COW-experiment is interpreted. This is done by using a new path equation other than the geodesic one. It is shown that this discrepancy is possibly due to a type of interaction between the torsion, of space-time generated by the background field, and the spin of the moving neutron. The results obtained are discussed and compared with the experimental interpretation suggested by Arif et al. in 1994. As a byproduct, an upper limit is imposed on the free parameter of the new path equation used.

gr-qc↗

Cosmological Application of the New General Relativity

The field equations of the new general relativity constructed by Hayashi and Shirafuji (1979), have been applied to two different geometric structures, given by Robertson (1932), in the domain of cosmology. In the first application a family of models, involving two of the parameters characterizing the field equations of the new general relativity, is obtained. In the second application the models obtained are found to involve one parameter only. The cosmological parameters in both applications are calculated and some cosmological problems are discussed in comparison with the corresponding results of other field theories.

gr-qc↗

Energy-Momentum Complex in Møller's Tetrad Theory of Gravitation

Møller's Tetrad Theory of Gravitation is examined with regard to the energy-momentum complex. The energy-momentum complex as well as the superpotential associated with Møller's theory are derived. Møller's field equations are solved in the case of spherical symmetry. Two different solutions, giving rise to the same metric, are obtained. The energy associated with one solution is found to be twice the energy associated with the other. Some suggestions to get out of this inconsistency are discussed at the end of the paper.

gr-qc↗