English
Related papers

Related papers: Field Equations and Radial Solution in a Noncommut…

200 papers

We introduce a two-parameter static, nonspherically-symmetric black hole solution in the Einstein theory of gravity coupled with a massless scalar field. The scalar field depends only on the polar coordinate $\theta$ in the spherical…

General Relativity and Quantum Cosmology · Physics 2025-02-21 S. Habib Mazharimousavi

A 2D symmetric teleparallel gravity model is given by a generic 4-parameter action that is quadratic in the non-metricity tensor. Variational field equations are derived. A class of conformally flat solutions is given. We also discuss…

High Energy Physics - Theory · Physics 2008-11-26 M. Adak , T. Dereli

In general relativity (GR), the metric tensor of spacetime is essential since it represents the gravitational potential. In other gauge theories (such as electromagnetism), the so-called premetric approach succeeds in separating the purely…

General Relativity and Quantum Cosmology · Physics 2017-04-18 Yakov Itin , Friedrich W. Hehl , Yuri N. Obukhov

Although the autoparallel curves and the geodesics coincide in the Riemannian geometry in which only the curvature is nonzero among the nonmetricity, the torsion and the curvature, they define different curves in the non-Riemannian ones. We…

General Physics · Physics 2022-02-15 Muzaffer Adak , Caglar Pala

The proposal of this work is to provide an answer to the following question: is it possible to treat the metric of space-time - that in General Relativity (GR) describes the gravitational interaction - as an effective geometry? In other…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. Novello

The Covariant Canonical Gauge theory of Gravity is generalized by including at the Lagrangian level all possible quadratic curvature invariants. In this approach, the covariant Hamiltonian principle and the canonical transformation…

General Relativity and Quantum Cosmology · Physics 2018-12-05 David Benisty , Eduardo I. Guendelman , David Vasak , Jurgen Struckmeier , Horst Stoecker

The constructive gravity programme applied to electrodynamics with vacuum birefringence yields the---up to unknown gravitational constants---unique compatible gravity theory for the underlying non-metric geometry. Starting from a…

General Relativity and Quantum Cosmology · Physics 2020-09-17 Nils Alex

The covariant form of the field equations for two--dimensional $R^2$--gravity with torsion as well as its Hamiltonian formulation are shown to suggest the choice of the light--cone gauge. Further a one--to--one correspondence between the…

High Energy Physics - Theory · Physics 2009-10-22 Thomas Strobl

The spherically symmetric static solutions are searched for in some f(T) models of gravity theory with a Maxwell term. To do this, we demonstrate that reconstructing the Lagrangian of f(T) theories is sensitive to the choice of frame, and…

General Relativity and Quantum Cosmology · Physics 2011-08-11 Tower Wang

The quantum gravity is formulated based on gauge principle. The model discussed in this paper has local gravitational gauge symmetry and gravitational field is represented by gauge potential. A preliminary study on gravitational gauge group…

High Energy Physics - Theory · Physics 2018-01-17 Ning Wu

We propose an approach which, by combining insights from Loop Quantum Gravity (LQG), Topos theory, Non-commutative Geometry \`a la Connes, and spacetime relationalism, provides fertile ground for the search of an adequate spacetime picture…

General Relativity and Quantum Cosmology · Physics 2021-03-12 Alejandro Ascárate

A simple modification to Einstein's theory of gravity in terms of a non-Riemannian connection is examined. A new tensor-variational approach yields field equations that possess a covariance similar to the gauge covariance of…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Robin W Tucker , Charles Wang

We examine the hypothesis that space-time is a product of a continuous four-dimensional manifold times a finite space. A new tensorial notation is developed to present the various constructs of noncommutative geometry. In particular, this…

High Energy Physics - Theory · Physics 2014-11-20 Ali H. Chamseddine , Alain Connes

We propose an extension of the symmetric teleparallel gravity, in which the gravitational action $L$ is given by an arbitrary function $f$ of the nonmetricity $Q$ and of the trace of the matter energy-momentum tensor $T$, so that…

General Relativity and Quantum Cosmology · Physics 2020-05-19 Yixin Xu , Guangjie Li , Tiberiu Harko , Shi-Dong Liang

We propose a new relativistic Lorentz-invariant spin-noncommutative algebra. Using the Weyl ordering of noncommutative position operators, we build an analogue of the Moyal-Groenewald product for the proposed algebra. The Lagrange function…

High Energy Physics - Theory · Physics 2016-11-02 V. M. Vasyuta , V. M. Tkachuk

In theories such as teleparallel gravity and its extensions, the frame basis replaces the metric tensor as the primary object of study. A choice of coordinate system, frame basis and spin-connection must be made to obtain a solution from…

General Relativity and Quantum Cosmology · Physics 2024-02-28 A. A. Coley , R. J. van den Hoogen , D. D. McNutt

In this paper, we provide a vacuum solution with torsion in quadratic Riemann-curvature gravity. Physically, the solution means that vacuum can have a nonzero vacuum field with large torsion. We show that the Einstein-Hilbert action can be…

High Energy Physics - Theory · Physics 2012-09-04 Kouzou Nishida

In this brief review, I summarize the new development on the correspondence between noncommuative (NC) field theory and gravity, shortly referred to as the NCFT/Gravity correspondence. I elucidate why a gauge theory in NC spacetime should…

High Energy Physics - Theory · Physics 2010-10-27 Hyun Seok Yang

Einstein's celebrated theory of gravitation can be presented in three forms: general relativity, teleparallel gravity, and the rarely considered before symmetric teleparallel gravity. Extending the latter, we introduce a new class of…

General Relativity and Quantum Cosmology · Physics 2018-06-12 Laur Järv , Mihkel Rünkla , Margus Saal , Ott Vilson

We propose a mathematical structure, based on a noncommutative geometry, which combines essential aspects of general relativity and quantum mechanics, and leads to correct "limiting cases" of both these theories. We quantize a groupoid…

General Relativity and Quantum Cosmology · Physics 2009-10-30 M. Heller , W. Sasin