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Related papers: Plane-fronted waves in metric-affine gravity

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This work provides a short but comprehensible overview of some relevant aspects of metric-affine theories of gravity in relation to the physics and astrophysics of compact objects. We shall highlight the pertinence of this approach to…

General Relativity and Quantum Cosmology · Physics 2020-08-26 Diego Rubiera-Garcia

We generalize the formulation of the colliding gravitational waves to metric-affine theories and present an example of such kind of exact solutions. The plane waves are equipped with five symmetries and the resulting geometry after the…

General Relativity and Quantum Cosmology · Physics 2016-08-15 Alberto García , Claus Lämmerzahl , Alfredo Macías , Eckehard W. Mielke , José Socorro

We consider the evolution of electromagnetic fields in curved spacetimes and calculate the exact wave equations of the associated electric and magnetic components. Our analysis is fully covariant, applies to a general spacetime and isolates…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Christos G. Tsagas

This Thesis is devoted to the study of Metric-Affine Theories of Gravity and Applications to Cosmology. The thesis is organized as follows. In the first Chapter we define the various geometrical quantities that characterize a non-Riemannian…

General Relativity and Quantum Cosmology · Physics 2019-02-27 Damianos Iosifidis

Above Planck energies, the spacetime might become non--Riemannian, as it is known fron string theory and inflation. Then geometries arise in which nonmetricity and torsion appear as field strengths, side by side with curvature. By gauging…

General Relativity and Quantum Cosmology · Physics 2016-08-15 José Socorro , Claus Lämmerzahl , Alfredo Macías , Eckehard W. Mielke

The metric-affine gauge theory of gravity provides a broad framework in which gauge theories of gravity can be formulated. In this article we fit metric-affine gravity into the covariant BRST--antifield formalism in order to obtain gauge…

High Energy Physics - Theory · Physics 2009-10-30 Frank Gronwald

The spacetime of the metric-affine gauge theory of gravity (MAG) encompasses {\it nonmetricity} and {\it torsion} as post-Riemannian structures. The sources of MAG are the conserved currents of energy-momentum and dilation, shear and spin.…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Yu. N. Obukhov , E. J. Vlachynsky , W. Esser , R. Tresguerres , F. W. Hehl

In this work, we focus on the theory of Gravito-Electromagnetism (GEM) -- the theory that describes the dynamics of the gravitational field in terms of quantities met in Electromagnetism -- and we propose two novel forms of metric…

General Relativity and Quantum Cosmology · Physics 2017-03-13 Athanasios Bakopoulos , Panagiota Kanti

We study the interaction among gravitational and electromagnetic plane waves by means of an analogue electromagnetic model of gravity, where the gravitational properties are encoded in the electromagnetic properties of a material in flat…

Gravitational waves (GWs) can undoubtedly serve as a messenger from the early Universe acting as well as a novel probe of the underlying gravity theory. In this work, motivated by one-loop vacuum-polarization effects on curved spacetime, we…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-02 Theodoros Papanikolaou , Charalampos Tzerefos , Salvatore Capozziello , Gaetano Lambiase

The family of metrics corresponding to the plane-fronted gravitational waves with parallel propagation, commonly referred to as the family of pp-wave metrics, is studied in the context of various modified gravitational models in a…

General Relativity and Quantum Cosmology · Physics 2017-04-21 Ahmet Baykal

The paper studies the inferences of wave equations for electromagnetic fields when there are gravitational fields at the same time. In the description with the algebra of octonions, the inferences of wave equations are identical with that…

General Physics · Physics 2010-08-13 Zi-Hua Weng

A four-vector field in flat space-time, satisfying a gauge-invariant set of second-order differential equations, is considered as a unified field. The model variational principle corresponds to the general covariance idea and gives rise to…

High Energy Physics - Theory · Physics 2008-11-26 Alexander A. Chernitskii

Geometrical structure of homogeneous isotropic models in the frame of the metric-affine gauge theory of gravity (MAGT) is analyzed. By using general form of gravitational Lagrangian including both a scalar curvature and various invariants…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. V. Minkevich , A. S. Garkun

We examine gravitational waves in an isolated axi--symmetric reflexion symmetric NGT system. The structure of the vacuum field equations is analyzed and the exact solutions for the field variables in the metric tensor are found in the form…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. W. Moffat , D. C. Tatarski

In this review we consider the quadratic Metric-Affine Gauge gravity Lagrangian, which contains all the algebraic invariants up to quadratic order in torsion, nonmetricity and curvature. The goal will be to collect the known exact solutions…

General Relativity and Quantum Cosmology · Physics 2022-11-09 Alejandro Jiménez-Cano

In this paper we deal with quadratic metric-affine gravity, which we briefly introduce, explain and give historical and physical reasons for using this particular theory of gravity. Further, we introduce a generalisation of well known…

General Relativity and Quantum Cosmology · Physics 2014-09-04 Vedad Pasic , Elvis Barakovic

We examine gravitational waves in an isolated axi--symmetric reflexion symmetric NGT system. The structure of the vacuum field equations is analyzed and the exact solutions for the field variables in the metric tensor are found in the form…

General Relativity and Quantum Cosmology · Physics 2015-06-25 N. J. Cornish , J. W. Moffat , D. C. Tatarski

We investigate gravitational waves in the $f(Q)$ gravity, i.e., a geometric theory of gravity described by a non-metric compatible connection, free from torsion and curvature, known as symmetric-teleparallel gravity. We show that $f(Q)$…

General Relativity and Quantum Cosmology · Physics 2024-02-02 Salvatore Capozziello , Maurizio Capriolo , Shin'ichi Nojiri

Electromagnetic radiation of a relativistic gas or plasma jet in the field of a plane gravitational wave is investigated. The gravitational wave is considered as a weak (linearized) field on flat Minkowski spacetime. It is assumed that the…

General Relativity and Quantum Cosmology · Physics 2024-12-13 Vladimir Epp , Konstantin Osetrin , Elena Osetrina