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The Lagrangian formulation of classical field theories and in particular general relativity leads to a coordinate-free, fully covariant analysis of these constrained systems. This paper applies multisymplectic techniques to obtain the…

General Relativity and Quantum Cosmology · Physics 2010-11-01 G. Esposito , C. Stornaiolo , G. Gionti

It is offered that $F(R)-$modified gravities can be considered as nonperturbative quantum effects arising from Einstein gravity. It is assumed that nonperturbative quantum effects gives rise to the fact that the connection becomes…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Vladimir Dzhunushaliev

We present a new finite action for Einstein gravity in which the Lagrangian is quadratic in the covariant derivative of a spinor field. Via a new spinor-curvature identity, it is related to the standard Einstein-Hilbert Lagrangian by a…

General Relativity and Quantum Cosmology · Physics 2010-11-01 James M. Nester , Roh Suan Tung

In the Regge-Teitelboim model, gravity is described by embedding the space-time manifold in a (usually flat) fixed higher-dimensional background, where the embedding coordinates, rather than the metric tensor, are the dynamical degrees of…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-30 S. R. Pinto , C. J. A. P. Martins

In this letter, we consider the theory of $F(R)$ gravity with the lagrangian density $ \pounds = R+\alpha R^2 + \beta R^2 \ln \beta R $. We obtain the constant curvature solutions and find the scalar potential of the gravitational field. We…

General Relativity and Quantum Cosmology · Physics 2016-06-09 J. Sadeghi , H. Farahani

We consider various mechanisms of modifying the effect of intrinsic curvature in gravity with respect to general relativity. Two primary approaches are studied. First, by considering a Lagrange multiplier or an auxiliary field. Second, by…

General Relativity and Quantum Cosmology · Physics 2025-07-08 Ido Ben-Dayan , Elena Emtsova

In this article we present a particular theory of gravity in which Einstein's field equations are modified by promoting Newton's constant $G$ to a covariant differential operator $G_\Lambda(\Box_g)$. The general idea was obviously outlined…

General Relativity and Quantum Cosmology · Physics 2016-07-15 Alain Dirkes

This paper has been withdrawn by the author after further work showed the proposed theoretical approach cannot fit planetary perihelion precession data. As presented, the theory doesn't fit gravitational light deflection by the sun either,…

General Physics · Physics 2014-03-28 Steven Kenneth Kauffmann

This work is mainly devoted to constructing a multisymplectic description of Lovelock's gravity, which is an extension of General Relativity. We establish a Griffiths variational problem for the Lovelock Lagrangian, obtaining the geometric…

Mathematical Physics · Physics 2020-10-05 Santiago Capriotti , Jordi Gaset , Narciso Román-Roy , Leandro Salomone

Previous work in the literature has studied the Hamiltonian structure of an R-squared model of gravity with torsion in a closed Friedmann-Robertson-Walker universe. Within the framework of Dirac's theory, torsion is found to lead to a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Giampiero Esposito , Gabriele Gionti , Giuseppe Marmo , Cosimo Stornaiolo

General relativity is highly successful in explaining a wide range of gravitational phenomena including the gravitational waves emitted by binary systems and the shadows cast by supermassive black holes. From a modern perspective the theory…

General Relativity and Quantum Cosmology · Physics 2024-07-26 Jesse Daas , Cristobal Laporte , Frank Saueressig , Tim van Dijk

The purely affine, metric-affine and purely metric formulation of general relativity are dynamically equivalent and the relation between them is analogous to the Legendre relation between the Lagrangian and Hamiltonian dynamics. We show…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Nikodem J. Poplawski

Extended Theories of Gravity can be considered a new paradigm to cure shortcomings of General Relativity at infrared and ultraviolet scales. They are an approach that, by preserving the undoubtedly positive results of Einstein's Theory, is…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Salvatore Capozziello , Mariafelicia De Laurentis

We give an alternative description of the physical content of general relativity that does not require a Lorentz invariant spacetime. Instead, we find that gravity admits a dual description in terms of a theory where local size is…

General Relativity and Quantum Cosmology · Physics 2011-03-30 Henrique Gomes , Sean Gryb , Tim Koslowski

In gravity theories derived from a f(R) Lagrangian, matter is usually supposed to be minimally coupled to the metric, which hence defines a ``Jordan frame.'' However, since the field equations are fourth order, gravity possesses an extra…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Nathalie Deruelle , Misao Sasaki , Yuuiti Sendouda

We investigate torsion-driven cosmological dynamics within the framework of Einstein-Cartan gravity using the De Donder-Weyl Hamiltonian formalism, where the tetrad and Lorentz connection act as independent variables and the Hamiltonian…

General Relativity and Quantum Cosmology · Physics 2026-02-18 Aarav Shah , M. Yu. Khlopov , M. Krasnov

The so-called $\Gamma\Gamma$-form of the gravitational Lagrangian, long known to provide its most compact expression as well as the most efficient generation of the graviton vertices, is taken as the starting point for discussing General…

High Energy Physics - Theory · Physics 2017-10-25 E. T. Tomboulis

We present a geometrical gravitational theory which reduces to Einstein's theory for weak gravitational potentials and which has a singularity-free analog of the Schwarzschild metric.

General Relativity and Quantum Cosmology · Physics 2009-10-22 Neil J. Cornish , John W. Moffat

Einstenian cubic gravity (ECG) is a modified theory of gravity constructed with cubic contractions of the curvature tensor. This theory has the remarkable feature of having the same two propagating degrees of freedom of Einstein gravity…

General Relativity and Quantum Cosmology · Physics 2024-06-04 L. A. Lessa , R. V. Maluf , J. E. G. Silva , C. A. S. Almeida

Gravitational wave observations have great potential to reveal new information about the fundamental nature of gravity, but extracting that information can be difficult. One popular technique is the parametrized inspiral test of general…

General Relativity and Quantum Cosmology · Physics 2022-06-29 Scott Perkins , Nicolas Yunes
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