Towards Energy tensor of Gravitational Field

Journal of Applied Mathematics and Physics, 2020

The paper belongs to the sphere of quantum physics, physics of waves and physical fields, in particular-to the gravitation. Their study provides a better understanding of the problems of natural sciences at all levels, from elementary particles, to Universe as a whole. Therefore, the solution of these problems is an urgent and important task, which to the works of many generations of scientists of the world was dedicated. However, they have not been fully resolved. In well-known works, including general relativity, determination of the wave and energy parameters of the gravitational field of the Universe and their numerical values are absent. Solutions found are limited to tensor equations of a general form, which allows their interpretation of over a wide range. Other disadvantages of famous models are: 1) the voluminous world of the Universe reduced to the planes on which space objects and other objects move, sagging planes due to their own mass; 2) signs of "top" and "bottom" of the system, which are not in the real Universe, just as they are not on Earth and not in the Solar system; 3) the formation of "voids" between the object and the curved space and others. Main goals of the work to identify these contradictions and find ways to resolve them are performed. The main difference and the scientific novelty of the work performed are the justification of the gravity model based on a rigorous determination of the wave and energy parameters of the gravitational field of the Universe and their numerical values. The initial parameters of this worked-is the frequency oscillation ν G of the waves of the gravitational field (Nastasenko's constant) found in 2011. Research Results: Knowing ν G can find all wave parameters of the gravitational field and their numerical values. The proposed new spatial-wave model of the action of gravity is based on the wave parameters of the gravitational fields of material objects. In the framework of their unity with electromagnetic fields, it reduces their structures to similar ones and eliminates the How to cite this paper: Nastasenko, V. (2020) Analysis of the Processes of Gravity in the Framework of Curvature of Space and the Substantiation of the New Model.

Reports on Mathematical Physics, 2012

In this paper we show how a gravitational field generated by a given energy-momentum distribution (for all realistic cases) can be represented by distinct geometrical structures (Lorentzian, teleparallel and non null nonmetricity spacetimes) or that we even can dispense all those geometrical structures and simply represent the gravitational field as a field, in the Faraday's sense, living in Minkowski spacetime. The explicit Lagrangian density for this theory is given and the field equations (which are a set of four Maxwell's like equations) are shown to be equivalent to Einstein's equations. We also analyze if the teleparallel formulation can give a mathematical meaning to "Einstein's most happy thought", i.e. the equivalence principle. Moreover we discuss the Hamiltonian formalism for for our theory and its relation to one of the possible concepts for energy of the gravitational field which emerges from it and the concept of ADM energy. One of the main results of the paper is the identification in our theory of a legitimate energy-momentum tensor for the gravitational field expressible through a really nice formula. * This article is based on a talk given by the author at the 9 th International Conference on Cliffor Algebras and their Applications (ICCA9) Weimar, 15-20 July 2011.

2009

We give a fully covariant energy momentum stress tensor for the gravitational field which is easily physically motivated, and which leads to a very general derivation of the Einstein equation for gravity. We do not need to assume any property of the surce matter fields' energy momentum stress tensor other than symmetry. We give a physical motivation for this choice

The paper shows how a generalization of the elasticity theory to four dimensions and to spacetime allows for a consistent description of the homogeneous and isotropic universe, including the accelerated expansion. The analogy is manifested by the inclusion in the traditional Lagrangian of general relativity of an additional term accounting for the strain induced in the manifold (i.e. in space-time) by the curvature, be it induced by the presence of a texture defect or by a matter/energy distribution. The additional term is sufficient to account for various observed features of the universe and to give a simple interpretation for the so called dark energy. Then, we show how the same approach can be adopted back in three dimensions to obtain the equilibrium configuration of a given solid subject to strain induced by defects or applied forces. Finally, it is shown how concepts coming from the familiar elasticity theory can inspire new approaches to cosmology and in return how methods appropriated to General Relativity can be applied back to classical problems of elastic deformations in three dimensions.

2020

We give a justification for generalizing the notion of energy momentum stress tensor in general relativity which results in the Jacobi curvature tensor being the embodiment of total energy momentum stress including gravity in general relativity. Mathematics Subject Classification (2000) : 83C05, 83C40, 83C99.

General Relativity and Gravitation, 2000

We study the dynamical description of gravity, the appropriate definition of the scalar field energymomentum tensor, and the interrelation between them in scalar-tensor theories of gravity. We show that the quantity which one would naively identify as the energy-momentum tensor of the scalar field is not appropriate because it is spoiled by a part of the dynamical description of gravity. A new connection can be defined in terms of which the full dynamical description of gravity is explicit, and the correct scalar field energy-momentum tensor can be immediately identified. Certain inequalities must be imposed on the two free functions (the coupling function and the potential) that define a particular scalar-tensor theory, to ensure that the scalar field energy density never becomes negative. The correct dynamical description leads naturally to the Einstein frame formulation of scalar-tensor gravity which is also studied in detail.

Classical and Quantum Gravity, 2010

The classical theory of strain in material continua is reviewed and generalized to space-time. Strain is attributed to "external" (matter/energy fields) and intrinsic sources fixing the global symmetry of the universe (defects in the continuum). A Lagrangian for space-time is worked out, adding to the usual Hilbert term an "elastic" contribution from intrinsic strain. This approach is equivalent to a peculiar tensor field, which is indeed part of the metric tensor. The theory gives a configuration of space-time accounting both for the initial inflation and for the late acceleration. Considering also the contribution from matter the theory is used to fit the luminosity data of type Ia supernovae, giving satisfactory results. Finally the Newtonian limit of the theory is obtained.

2008

We give a derivation of the Einstein equation for gravity which employs a definition of the local energy density of the gravitational field as a symmetric second rank tensor whose value for each observer gives the trace of the spatial part of the energy-stress tensor as seen by that observer. We give a physical motivation for this choice using light pressure. Mathematics Subject Classification (2000) : 83C05, 83C40, 83C99.

General Relativity and Gravitation, 2008

The elasticity difference tensor, used in [1] to describe elasticity properties of a continuous medium filling a space-time, is here analysed. Principal directions associated with this tensor are compared with eigendirections of the material metric. Examples concerning spherically symmetric and axially symmetric space-times are then presented.

arXiv (Cornell University), 2014

In the literature one often finds the claim that there is no such thing as an energy-momentum tensor for the gravitational field, and consequently, that the total energy-momentum conservation can only be defined in terms of a gravitational energy-momentum pseudo-tensor. Nevertheless, by relaxing the assumption that gravitational energy-momentum tensor should only depend on first derivatives of the metric, the Einstein equation leads to a trivial result that gravitational energy-momentum tensor is essentially the Einstein tensor. We discuss various peculiarities of such a definition of energy-momentum are argue that all these peculiarities have a sensible physical interpretation.