The Experts below are selected from a list of 5919 Experts worldwide ranked by ideXlab platform
Luca Fabbri - One of the best experts on this subject based on the ideXlab platform.
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Restrictions on Torsion–spinor field theory
Modern Physics Letters A, 2019Co-Authors: Luca Fabbri, Manuel TecchiolliAbstract:Torsion propagation and Torsion–spin coupling are studied in the perspective of the Velo–Zwanziger method of analysis; specifically, we write the most extensive dynamics of the Torsion Tensor and t...
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Continuity of the Torsionless limit as a selection rule for gravity theories with Torsion
Physical Review D, 2014Co-Authors: Luca Fabbri, Philip D. MannheimAbstract:While one can in principle augment gravity theory with Torsion, it is generally thought that any such Torsion affects would be too small to be of consequence. Here we show that this cannot in general be the case. We show that the limit of vanishing Torsion is not necessarily a continuous one, with the theory obtained in the limit not necessarily coinciding with the theory in which Torsion had never been present at all. However, for a standard Torsion Tensor that is antisymmetric in two of its indices we have found two cases in which the vanishing Torsion limit is in fact continuous, namely Einstein gravity and conformal gravity. For other gravity theories of common interest to possess a continuous limit the Torsion Tensor would need to be antisymmetric in all three of its indices.
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from the Torsion Tensor for spinors to the weak forces for leptons
arXiv: High Energy Physics - Theory, 2010Co-Authors: Luca FabbriAbstract:We consider a geometric approach to field theory in which Torsion is present beside gravity and also electrodynamics for the matter field equations, and we develop the consequences of the Torsion-spin coupling for the spinor fields; we show that these interactions have the structure of the weak interactions acting among leptons: we discuss the implications for the standard model of fundamental interactions of elementary fields in the perspective of the foundations of unification in theoretical physics.
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On a Completely Antisymmetric Cartan Torsion Tensor
arXiv: General Relativity and Quantum Cosmology, 2006Co-Authors: Luca FabbriAbstract:We discuss the general structure of metric geometries, and how metricity implies the complete antisymmetry of Cartan Tensor; an application in the frame of Lie group theory is given. Interpretations of the completely antisymmetric Torsion in physical models are reviewed.
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On a Completely Antisymmetric Cartan Torsion Tensor
2006Co-Authors: Luca FabbriAbstract:Nous discutons la structure generale des geometries metriques, et comment la metricite implique un tenseur de Cartan completement antisymetrique; une application dans le cadre de la theorie du groupe de Lie sera donnee en exemple. Une revue des interpretations d'une Torsion completement antisymetrique a l'interieur de modeles physiques sera effectuee.
I. A. Gordeeva - One of the best experts on this subject based on the ideXlab platform.
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Three classes of Weitzenböck manifolds
Russian Mathematics, 2011Co-Authors: I. A. Gordeeva, S. E. StepanovAbstract:A Weitzenbock manifold is a triplet defined by a differentiable manifold with a metric g of certain signature and a linear connection with zero curvature Tensor and nonzero Torsion Tensor which is a metric connection with respect to g. The theory of such manifolds is called the “new theory of gravity”. We study properties of three classes of Weitzenbock manifolds and prove some vanishing thorems.
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Vanishing theorems for some classes of Riemann–Cartan manifolds
Journal of Mathematical Sciences, 2011Co-Authors: I. A. GordeevaAbstract:In this paper, a classification of Riemann–Cartan manifolds based on the orthogonal decomposition of the Torsion Tensor is given. Problems on the existence of two classes ℘_1 ⨁ ℘_2 and ℘_3 of Riemann–Cartan spaces are discussed.
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VANISHING THEOREMS FOR SOME CLASSES OF RIEMANN-CARTAN MANIFOLDS
Journal of Mathematical Sciences, 2011Co-Authors: I. A. GordeevaAbstract:In this paper, a classification of Riemann–Cartan manifolds based on the orthogonal decomposition of the Torsion Tensor is given. Problems on the existence of two classes ℘1 ⨁ ℘2 and ℘3 of Riemann–Cartan spaces are discussed.
Joydeep Sengupta - One of the best experts on this subject based on the ideXlab platform.
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Semi-symmetric metric connection with pseudo-symmetric Torsion Tensor
Lobachevskii Journal of Mathematics, 2012Co-Authors: Joydeep Sengupta, Bijita Biswas, A. KonarAbstract:The object of the present paper is to study a Riemannian manifold admitting a semisymmetric metric connection with pseudo-symmetric Torsion Tensor.
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On Semi Pseudo Symmetric Manifolds Admitting a Type of Quarter Symmetric Metric Connection
2011Co-Authors: M. Tarafdar, Joydeep SenguptaAbstract:The present paper deals with Semi Pseudo Symmetric manifolds (SPS) n ( n> 3) admitting a quarter-symmetric metric connection ∇ whose Torsion Tensor T is given by
Pei Biao Zhao - One of the best experts on this subject based on the ideXlab platform.
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A SPECIAL TYPE OF SEMI-SYMMETRIC NON-METRIC CONNECTION ON A RIEMANNIAN MANIFOLD
2016Co-Authors: Yan Ling Han, Pei Biao ZhaoAbstract:The object of the present paper is to study a Riemannian manifold admitting a type of semi-symmetric non-metric connection whose Torsion Tensor is pseudo symmetric.
Csaba Vincze - One of the best experts on this subject based on the ideXlab platform.
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On compatible linear connections with totally anti-symmetric Torsion Tensor of three-dimensional generalized Berwald manifolds
Beiträge zur Algebra und Geometrie Contributions to Algebra and Geometry, 2019Co-Authors: Csaba VinczeAbstract:Generalized Berwald manifolds are Finsler manifolds admitting linear connections such that the parallel transports preserve the Finslerian length of tangent vectors. By the fundamental result of the theory (Vincze in J AMAPN 21:199–204, 2005) such a linear connection must be metrical with respect to the averaged Riemannian metric given by integration of the Riemann–Finsler metric on the indicatrix hypersurfaces. Therefore the linear connection is uniquely determined by its Torsion Tensor. If the Torsion is zero then we have a classical Berwald manifolds. Otherwise the Torsion is a strange data we need to express in terms of quantities of the Finsler manifold. In the paper we are going to give explicit formulas for the linear connections with totally anti-symmetric Torsion Tensor of three-dimensional generalized Berwald manifolds (Theorem 2). The results are based on averaging of (intrinsic) Finslerian quantities by integration over the indicatrix surfaces. They imply some consequences for the base manifold as a Riemannian space with respect to the averaged Riemannian metric (Theorems 3 and 4). The possible cases are Riemannian spaces of constant zero curvature, constant positive curvature or Riemannian spaces admitting Killing vector fields of constant Riemannian length.
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On compatible linear connections with totally anti-symmetric Torsion Tensor of three-dimensional generalized Berwald manifolds
arXiv: Differential Geometry, 2019Co-Authors: Csaba VinczeAbstract:Generalized Berwald manifolds are Finsler manifolds admitting linear connections such that the parallel transports preserve the Finslerian length of tangent vectors. By the fundamental result of the theory \cite{V5} such a linear connection must be metrical with respect to the averaged Riemannian metric given by integration of the Riemann-Finsler metric on the indicatrix hypersurfaces. Therefore the linear connection is uniquely determined by its Torsion Tensor. If the Torsion is zero then we have a classical Berwald manifolds. Otherwise the Torsion is a strange data we need to express in terms of quantities of the Finsler manifold. In the paper we are going to give explicit formulas for the linear connections with totally anti-symmetric Torsion Tensor of three-dimensional generalized Berwald manifolds. The results are based on averaging of (intrinsic) Finslerian quantities by integration over the indicatrix surfaces. They imply some consequences for the base manifold as a Riemannian space with respect to the averaged Riemannian metric. The possible cases are Riemannian spaces of constant zero curvature, constant positive curvature or Riemannian spaces admitting Killing vector fields of constant Riemannian length.