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For explicitly time depending mass density, which satisfies a continuity equation, it is shown that Maxwell-like equations for gravitational field follow naturally without any need of General Relativity Theory approximation or related…

General Physics · Physics 2017-11-23 Gustavo V. Lopez

The space-time curvature carried by electromagnetic fields is discovered and a new unification of geometry and electromagnetism is found. Curvature is invariant under charge reversal symmetry. Electromagnetic field equations are examined…

General Relativity and Quantum Cosmology · Physics 2007-05-23 R. W. M. Woodside

We demonstrate that the emergence of a curved spacetime ``effective Lorentzian geometry'' is a common and generic result of linearizing a field theory around some non-trivial background. This investigation is motivated by considering the…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Carlos Barcelo , Stefano Liberati , Matt Visser

Emergent modified gravity has shown that the canonical formulation of general relativity gives rise to a larger class of covariant modifications than action-based approaches, so far in symmetry-reduced models. This outcome is made possible…

General Relativity and Quantum Cosmology · Physics 2026-04-29 Martin Bojowald , Manuel Diaz , Erick I. Duque

It is possible to implement a certain form of modified gravity inspired by loop quantization through non-bijective canonical transformations. The canonical nature might suggest that such modifications are guaranteed to preserve general…

General Relativity and Quantum Cosmology · Physics 2021-07-07 Martin Bojowald

Using the Einstein energy-mass relation and a concept of cross-correlating material unit-fields (pp. 1-148), the quantum equation for united gravitation and electromagnetism is derived (pp. 148-164). The unified equation yields all known…

General Physics · Physics 2017-07-26 S. V. Kukhlevsky

We propose a step-by-step manual for the construction of alternative theories of gravity, perturbatively as well as nonperturbatively. The construction is guided by no more than two fundamental principles that we impose on the gravitational…

General Relativity and Quantum Cosmology · Physics 2020-09-22 Nils Alex , Tobias Reinhart

From a covariant Hamiltonian formulation, by using symplectic ideas, we obtain certain covariant boundary expressions for the quasilocal quantities of general relativity and other geometric gravity theories. The contribution from each of…

General Relativity and Quantum Cosmology · Physics 2014-11-17 C. M. Chen , J. M. Nester

We propose an effective non-relativistic framework in which wave-function collapse emerges as a deterministic dynamical instability induced by gravitational self-interaction and regulated by short-distance repulsion. The dynamics is…

Quantum Physics · Physics 2026-04-20 C. A. S. Almeida

A nonlocal form of the effective gravitational action could cure the unboundedness of euclidean gravity with Einstein action. On sub-horizon length scales the modified gravitational field equations seem compatible with all present tests of…

General Relativity and Quantum Cosmology · Physics 2015-06-25 C. Wetterich

The canonical quantum theory of gravity -- Quantum Geometrodynamics (QG) is applied to the homogeneous Bianchi type IX cosmological model. As a result, the framework for the quantum theory of homogeneous cosmologies is developed. We show…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Arkady Kheyfets , Warner A. Miller , Ruslan Vaulin

The governing equations of Maxwell electrodynamics in multi-dimensional spaces are derived from the variational principle of least action which is applied to the action function of the electromagnetic field. The Hamiltonian approach for the…

General Physics · Physics 2023-06-13 Alexei M. Frolov

We show that the self-interactions present in the effective field theory formulation of general relativity can couple gravitational wave modes and generate nonclassical states. The output of gravitational nonlinear processes can also be…

General Relativity and Quantum Cosmology · Physics 2025-12-05 Thiago Guerreiro

Riemannian and teleparallel geometrical approaches to the investigation of Maxwell electrodynamics shown that a unified field theory of gravitation and electromagnetism a la Einstein can be obtained from a stationary metric. This idea…

General Relativity and Quantum Cosmology · Physics 2007-05-23 L. C. Garcia de Andrade

In a wide range of quantum gravity theories, quasiclassical geometries, which are solutions to the Einstein field equations approximately, are described by "coherent states." Here we propose a Hamiltonian formalism for gravitational…

General Relativity and Quantum Cosmology · Physics 2025-12-01 Sijia Wang , Achintya Sajeendran , Dong-han Yeom , Robert B. Mann , Joshua Foo

Real world quantum systems are open to perpetual influence from the wider environment. Quantum gravitational fluctuations provide a most fundamental source of the environmental influence through their universal interactions with all forms…

Quantum Physics · Physics 2016-02-10 Teodora Oniga , Charles H. -T. Wang

The possibility of the extension of spatial diffeomorphisms to a larger family of symmetries in a class of classical field theories is studied. The generator of the additional local symmetry contains a quadratic kinetic term and a potential…

High Energy Physics - Theory · Physics 2015-05-18 Szilard Farkas , Emil J. Martinec

Emergent modified gravity presents a new class of gravitational theories in which the structure of space-time with Riemannian geometry of a certain signature is not presupposed. Relying on crucial features of a canonical formulation, the…

General Relativity and Quantum Cosmology · Physics 2024-04-09 Martin Bojowald , Erick I. Duque , Dennis Hartmann

The behaviour of a "test" electromagnetic field in the background of an exact gravitational plane wave is investigated in the framework of Einstein's general relativity. We have expressed the general solution to the de Rham equations as a…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Enrico Montanari , Mirco Calura

Newtonian gravity arises as the nonrelativistic, static, weak-field limit of some Lorentzian spacetime geometry solving the generally covariant Einstein equations for a given matter field configuration. Spacetime geometry has a local…

General Relativity and Quantum Cosmology · Physics 2026-01-21 Martin Rainer