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Related papers: Generalising the coupling between spacetime and ma…

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We consider alternative theories of gravity with a direct coupling between matter and the Ricci scalar We study the relation between these theories and ordinary scalar-tensor gravity, or scalar-tensor theories which include non-standard…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Thomas P. Sotiriou , Valerio Faraoni

We generalize and unify the $f(R,T)$ and $f(R,L_m)$ type gravity models by assuming that the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar $R$, of the trace of the energy-momentum tensor $T$, and of the…

General Relativity and Quantum Cosmology · Physics 2021-07-28 Zahra Haghani , Tiberiu Harko

We discuss new models of an `affine' theory of gravity in multidimensional space-times with symmetric connections. We use and develop ideas of Weyl, Eddington, and Einstein, in particular, Einstein's proposal to specify the space - time…

High Energy Physics - Theory · Physics 2010-11-12 A. T. Filippov

The Einstein theories of space-time and gravity as well the stander cosmology are reconstructed thoroughly in this paper based on flat reference frame. The rational parts of the Einstein theories are reserved while the irrational parts…

General Physics · Physics 2007-05-23 Mei Xiaochun

The problem of explaining the acceleration of the expansion of the universe and the observational and theoretical difficulties associated with dark matter and dark energy are discussed. The possibility that Einstein gravity does not…

Astrophysics · Physics 2007-05-23 J. W. Moffat

In this work the approach for a description of the physical systems about whiches it is not possible to get basicly the total information is suggested. As a result the differential equations, the solutions of which characterize the physical…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Valery Koryukin

Loop quantum gravity is a perspective candidate for the quantum theory of gravity. However, there is a conceptual controversy in it: having started from the Einstein-Hilbert action and describing spacetime without matter, we can hardly…

General Relativity and Quantum Cosmology · Physics 2026-02-10 Mikhail Altaisky

Spacetime geometry is described by two -- {\em a priori} independent -- geometric structures: the symmetric connection $\Gamma$ and the metric tensor $g$. Metricity condition of $\Gamma$ (i.e. $\nabla g = 0$) is implied by the Palatini…

General Relativity and Quantum Cosmology · Physics 2024-03-15 B. Bąk , J. Kijowski

Extending black-hole entropy to ordinary objects, we propose kinetic entropy tensor, based on which a quantum gravity tensor equation is established. Our investigation results indicate that if N=1, the quantum gravity tensor equation…

General Physics · Physics 2016-06-11 Xu Duan

A unified description of all interactions could be based on a higher-dimensional theory involving only spinor fields. The metric arises as a composite object and the gravitational field equations contain torsion-corrections as compared to…

High Energy Physics - Theory · Physics 2009-02-20 A. Hebecker , C. Wetterich

A nonlocal generalization of Einstein's theory of gravitation is constructed within the framework of the translational gauge theory of gravity. In the linear approximation, the nonlocal theory can be interpreted as linearized general…

General Relativity and Quantum Cosmology · Physics 2009-03-24 Friedrich W. Hehl , Bahram Mashhoon

Gravity is derived from an entropic action coupling matter fields with geometry. The fundamental idea is to relate the metric of Lorentzian spacetime to a quantum operator, playing the role of an renormalizable effective density matrix and…

General Relativity and Quantum Cosmology · Physics 2025-03-20 Ginestra Bianconi

There exists some confusion, as evidenced in the literature, regarding the nature of the gravitational field in Einstein's General Theory of Relativity. It is argued here the this confusion is a result of a change in interpretation of the…

General Physics · Physics 2007-05-23 Peter M. Brown

Observed physical phenomena can be described well by quantum mechanics or general relativity. People may try to find an unified fundamental theory which mainly aims to merge gravity with quantum theory. However, difficulty in merging those…

General Physics · Physics 2009-11-10 Chang-Yu Zhu , Heng Fan

The geometric foundations of General Relativity are revisited, with particular attention to its gauge invariance, as a key to understanding the true nature of spacetime. Beyond the common image of spacetime as a deformable 'fabric' filling…

General Relativity and Quantum Cosmology · Physics 2025-10-17 Jaume de Haro , Emilio Elizalde

In the macroscopic gravity approach to the averaging problem in cosmology, the Einstein field equations on cosmological scales are modified by appropriate gravitational correlation terms. We present exact cosmological solutions to the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 A. A. Coley , N. Pelavas , R. M. Zalaletdinov

The simplest variant of gauge gravitation theory in Riemann-Cartan spacetime leading to the solution of the problem of cosmological singularity and dark energy problem is investigated. It is shown that this theory by certain restrictions on…

General Relativity and Quantum Cosmology · Physics 2017-12-06 A. V. Minkevich

Gravitation, according to General Relativity, is an attribute of space-time's geometry and hence not a force in the Newtonian sense. This is a consequence of Einstein's equivalence principle, which so far passed all experimental tests with…

Popular Physics · Physics 2013-09-10 Domenico Giulini

Spacetime curvature plays the primary role in general relativity but Einstein later considered a theory where torsion was the central quantity. Just as the Einstein-Hilbert action in the Ricci curvature scalar R can be generalized to f(R)…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-27 Eric V. Linder

In the general relativity theory the basic ingredient to describe gravity is the geometry, which interacts with all forms of matter and energy, and as such, the metric could be interpreted as a true physical quantity. However the metric is…

General Relativity and Quantum Cosmology · Physics 2025-03-19 Mario Novello , Júnior D. Toniato