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The averaging problem in general relativity is briefly discussed. A new setting of the problem as that of macroscopic description of gravitation is proposed. A covariant space-time averaging procedure is described. The structure of the…

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

A model for the static weak-field macroscopic medium is analyzed and the equation for the macroscopic gravitational potential is derived. This is a biharmonic equation which is a non-trivial generalization of the Poisson equation of…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Giovanni Montani , Remo Ruffini , Roustam Zalaletdinov

The averaging problem in cosmology and the approach of macroscopic gravity to resolve the problem is discussed. The averaged Einstein equations of macroscopic gravity are modified on cosmological scales by the macroscopic gravitational…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Roustam Zalaletdinov

The construction of an averaged theory of gravity based on Einstein's General Relativity is very difficult due to the non-linear nature of the gravitational field equations. This problem is further exacerbated by the difficulty in defining…

General Relativity and Quantum Cosmology · Physics 2010-04-16 R. J. van den Hoogen

In this paper, we establish a model-independent framework based on the Isaacson picture to analyze the gravitational-wave effects in the most general vector-tensor theory that yields second-order field equations. Within this framework, we…

General Relativity and Quantum Cosmology · Physics 2025-06-12 Yu-Qi Dong , Xiao-Bin Lai , Yu-Qiang Liu , Yu-Xiao Liu

We discuss the averaging problem in general relativity, using the form of the macroscopic gravity equations in the case of spherical symmetry in volume preserving coordinates. In particular, we calculate the form of the correlation tensor…

Astrophysics · Physics 2009-11-11 A. A. Coley , N. Pelavas

The search for the gravitational energy-momentum tensor is often qualified as an attempt of looking for ``the right answer to the wrong question''. This position does not seem convincing to us. We think that we have found the right answer…

General Relativity and Quantum Cosmology · Physics 2009-10-31 S V Babak , L P Grishchuk

A non-geometrical (but with curved space) theory of gravitation characterized by a vector field representing gravitational matter and a metric tensor presenting space is presented. It is derived from a more general theory of matter and…

General Relativity and Quantum Cosmology · Physics 2008-03-13 Boris Hikin

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

Only a severely restricted class of tensor fields can provide classical spacetime geometries, namely those that can carry matter field equations that are predictive, interpretable and quantizable. These three conditions on matter translate…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Kristina Giesel , Frederic P. Schuller , Christof Witte , Mattias N. R. Wohlfarth

A tensor description of perturbative Einsteinian gravity about an arbitrary background spacetime is developed. By analogy with the covariant laws of electromagnetism in spacetime, gravito-electromagnetic potentials and fields are defined to…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Simon J. Clark , Robin W. Tucker

We consider a gravitational model in which matter is non-minimally coupled to geometry, with the effective Lagrangian of the gravitational field being given by an arbitrary function of the Ricci scalar, the trace of the matter…

General Relativity and Quantum Cosmology · Physics 2024-11-18 Zahra Haghani , Tiberiu Harko , Francisco S. N. Lobo , Hamid Reza Sepangi , Shahab Shahidi

The theory of macroscopic gravity provides a formalism to average the Einstein field equations from small scales to largest scales in space-time. It is well known that averaging is an operation that does not commute with calculating the…

General Relativity and Quantum Cosmology · Physics 2023-12-12 Anish Agashe , Mustapha Ishak

Guided by the Einstein equivalence principle that identifies the phenomenon of gravitation as a manifestation of the dynamics of spacetime in contrast to a localizable force, we review and explore its consequences on formulating a theory of…

General Relativity and Quantum Cosmology · Physics 2025-06-02 Jann Zosso

We investigate propagation of gravitational waves in the most general teleparallel gravity model with second order field equations around the Minkowski background. We argue that in this case the most general Lagrangian at the first order of…

General Relativity and Quantum Cosmology · Physics 2020-07-08 Manuel Hohmann , Martin Krššák , Christian Pfeifer , Ulbossyn Ualikhanova

We discuss the propagation of gravitational waves over a non-Riemannian spacetime, when a non-minimal coupling between the geometry and matter is considered in the form of contractions of the energy momentum tensor with the Ricci and…

General Relativity and Quantum Cosmology · Physics 2025-12-16 Flavio Bombacigno , Fabio Moretti , Gonzalo J. Olmo

General relativity in the form where gravitational perturbations together with other physical fields propagate on an auxiliary background is considered. With using the Katz-Bi{\v{c}}\'ak-Lynden-Bell technique new conserved currents,…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. N. Petrov

A pedagogical description of a simple ungeometrical approach to General Relativity is given, which follows the pattern of well understood field theories, such as electrodynamics. This leads quickly to most of the important weak field…

Astrophysics · Physics 2007-05-23 Norbert Straumann

We solve the wave equation for gravitational waves emitted by compact objects systems using the Multipolar Post-Minkowskian (MPM) method, and in the presence of Lorentz invariance violating terms. We select a Lorentz-violating extension of…

General Relativity and Quantum Cosmology · Physics 2025-06-13 Samy Aoulad Lafkih , Marie-Christine Angonin , Christophe Le Poncin-Lafitte , Nils A. Nilsson

We develop a generic spacetime model in General Relativity which can be used to build any gravitational model within General Relativity. The generic model uses two types of assumptions: (a) Geometric assumptions additional to the inherent…

General Relativity and Quantum Cosmology · Physics 2021-06-15 Michael Tsamparlis , Andronikos Paliathanasis
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