Anisotropic massive strings in the scalar-tensor theory of gravitation

We present the model of an anisotropic universe with string fluid as the source of matter within the framework of the scalar-tensor theory of gravitation. An exact solution of field equations is obtained by applying Berman＇s law of variation to Hubble＇s parameter which yields a constant value of the deceleration parameter. The nature of classical potential is examined for the model under consideration. It has also been found that the massive strings dominate in the early universe and finally disap-pear from the universe. This is in agreement with current astronomical observations. The physical and dynamical properties of the model are also discussed.

Improved routing strategy based on gravitational field theory

Routing and path selection are crucial for many communication and logistic applications. We study the interaction between nodes and packets and establish a simple model for describing the attraction of the node to the packet in transmission process by using the gravitational field theory, considering the real and potential congestion of the nodes. On the basis of this model, we propose a gravitational field routing strategy that considers the attractions of all of the nodes on the travel path to the packet. In order to illustrate the efficiency of proposed routing algorithm, we introduce the order parameter to measure the throughput of the network by the critical value of phase transition from a free flow phase to a congested phase,and study the distribution of betweenness centrality and traffic jam. Simulations show that, compared with the shortest path routing strategy, the gravitational field routing strategy considerably enhances the throughput of the network and balances the traffic load, and nearly all of the nodes are used efficiently.

Light Propagation in the Second post-Newtonian Approximation of Scalar-Tensor Theory of Gravity

In this paper, we use the metric coefficients and the equation of motion obtained in the second post- Newtonian approximation of scalar-tensor theory to derive the second-order light propagation equation and the light deflection angle and compare it with previous works. These results are useful for precision astrometry missions like ASTROD, GALA, Darwin and SIM which aim at astrometry with micro-arcsecond and nano-aresecond accuracies, and need for the second post-Newtonian framework and ephemeris for observations to determine the stellar and spacecraft positions.

The Gravitational Potential and the Gravitational Force According to the Correct Schwarzschild Metric

In a recent article, we have corrected the traditional derivation of the Schwarzschild metric, thus obtaining the formulation of the correct Schwarzschild metric, which is different from the traditional Schwarzschild metric. In this article, by starting from this correct Schwarzschild metric, we obtain the formulas of the correct gravitational potential and of the correct gravitational force in the case described by this metric. Moreover, we analyse these correct results and their consequences. Finally, we propose some possible crucial experiments between the commonly accepted theory and the same theory corrected according to this article.

Refinement of Newton Gravitation Law

According to the theory of general relativity and experiments with atomic clocks in gravitation field, presence of the field shall cause time dilation of clock at rest in the field. This means that the gravitation constant G is not a true physical constant, but rather a function of the location of the setup in the field when measuring the parameter. This is because the definition of G includes a unit of time, and duration of that time unit is influenced by clock’s location in the field. However, the theory assumes a prior that G shall remain constant in gravitation field, even though this may not be the case. On the other hand, relativistic gravitation phenomena can be derived without contradiction from a refined version of Newton’s law of gravitation that complies with Einstein’s law of mass-energy equivalence.

A note on teleparallel Killing vector fields in Bianchi type Ⅷ and Ⅸ space-times in teleparallel theory of gravitation

In this paper we classify Bianchi type Ⅷ and IX space-times according to their teleparallel Killing vector fields in the teleparallel theory of gravitation by using a direct integration technique. It turns out that the dimensions of the teleparallel Killing vector fields are either 4 or 5. From the above study we have shown that the Killing vector fields for Bianchi type Ⅷ and Ⅸ space-times in the context of teleparallel theory are different from that in general relativity.

Bianchi type I in f(T) gravitational theories

A tetrad field that is homogeneous and anisotropic which contains two unknown functions A（t） and B（t） of cosmic time is applied to the field equations of f（T）, where T is the torsion scalar, T = T~μ_（νρ）S_μ^（νρ）. We calculate the equation of continuity and rewrite it as a product of two brackets, the first is a function of f（T） and the second is a function of the two unknowns A（t） and B（t）. We use two different relations between the two unknown functions A（t） and B（t） in the second bracket to solve it. Both of these relations give constant scalar torsion and solutions coincide with the de Sitter one. So,another assumption related to the contents of the matter fields is postulated. This assumption enables us to drive a solution with a non-constant value of the scalar torsion and a form of f（T） which represents ΛCDM.

THEORY OF GRAVITATIONAL RADIATION OF THE(Ω,A_μr)-FIELD

Further exploration of the fteld theory as first proposed by Yu (1989) is here presented to cover the equation of motion of a test particle which induces gravitational radiation. The same theory is shown to contain an exact gravitational radiation equation derived as a logical consequence of field equations without extra postulates. In this general dynamic context the theory is renamed 'The field Theory'.

Classical Theory of Advance of Perihelion of Mercury with Velocity Dependent Inertial and Gravitational Masses

It is shown that Mercury's motion of the perihelion around the Sun, which is believed to be explicable quantitatively only by general relativity, can be fully understood within the frame of the dynamics of special relativity. It is only necessary to take into consideration the relativistic dependence of the planet's inertial and gravitational masses on its velocity (relative to the Sun) in the conservation equations for energy, and linear and angular momenta in the gravitational field. The physical Problem is reduced to a singular, nonlinear differential equation, which is solved numerically for the planet Mercury. The advance of the perihelion of Mercury is shown to be = 42.087' for a period of 100 years, which is in agreement with the as- tronomical observations and the result (by analytical approximations) of general relativity.

Metric of Rotating Charged Spherical Mass in Vacuum for Vector Graviton Metric Theory of Gravitation

Based on the vector graviton metric theory of gravitation (VGM) suggested by one of the authors of this article, using the method of null tetrad and analytic continuation, this paper gives the metric of the rotating charged spherical mass in VGM. The result shows once again that a replacement of G by G* = G(1 - G M /2r) in general relativity will yield the corresponding result in VGM for the metric in vacuum.

A Possible Interpretation on Distance-Dependent Effect of Gravitational Constant in Newton＇s Theory of Gravitation

Based on the new metric theory of gravitation suggested by the author of this article, it gives a possible theoretical interpretation on the famous experiment done by D.R. Long in 1976, i.e. the distance-dependent effect of the gravitational constant in Newton's theory of gravitation.

A NEW MODELLING METHOD FOR EVALUATING EXTERNAL DISTURBING POTENTIAL BASED ON THEORY OF UNIFIED REPRESENTATION OF GRAVITATIONAL FIELD

For a special use a new modelling method of evaluating external disturbing potential is presented in this paper.Being different from classical methods in physical geodesy this method is grounded upon the theory of unified representation of gravitational field.The models created in this way are particularly satisfactory for a high_speed computation of gravitational field in low altitude because they take account of topographic effects and have their kernel functions with simple structure and weak singularity.

Reconstructing Equation of State for Dark Energy in Double Complex Symmetric Gravitational Theory

We propose to study the accelerating expansion of the universe in the double complex symmetric gravitational theory （DCSGT）. The universe we live in is taken as the real part of the whole spacetime MC^4（J）, which is double complex. By introducing the spatially flat FRW metric, not only the double Friedmann equations but also the two constraint conditions py = 0 and J^2 = 1 are obtained. Farthermore, using parametric DL（z） ansatz, we reconstruct the ω/（z） and V（Ф） for dark energy from real observational data. We find that in the two cases of J = i, pJ = 0, and J = ε, pJ≠0, the corresponding equations of state ω＇（z） remain close to -1 at present （z = 0） and change from below -1 to above -1. The results illustrate that the whole spacetime, i.e. the double complex spacetime MC^4（J）, may be either ordinary complex （J = i, pJ = 0） or hyperbolic complex （J = ε, pJ≠ 0）. And the fate of the universe would be Big Rip in the future.

Remarks to Gravitation Theories

Gravitation is one of the most significant phenomena which attract the attention of humankind for ages. There are twomost influential theories of the Gravitation at the current time being (summer 2019), namely, the Isaac Newton’s Theory ofGravitation and Albert Einstein’s General Theory of Relativity, which includes an explanation of the gravitation. However, both ofthem are incommensurate — so far — with plenty of quantum theories of the World. In this contribution, there is outlined a strategyfor unifying the current approaches to the Gravitation. Namely, that the gravitation/gravity should be considered as a consequence ofinteraction — a “pinning effect” — of the Spacetime with the non-integral spin of the Fermions, to saturate/add/ the missing part ofthem. It might induce a deformation/curvature of the Spacetime and known effects on moving material objects, as well aselectromagnetic radiation, including light, and other types of radiation, and properties/parameters of transformations of fields,described in the General Theory of Relativity and another. It is Gravitation which modifies/creates Spacetime curvature and itsfeatures and not vice versa.

Dark Matter: An Odd Need Created by Unsuitable Theories of Gravitation. The Higgs Quantum Space Dynamics Gravity Doesn’t Need It

The Higgs theory introduces the idea that space is filled up throughout by a quantum fluid medium, giving mass and mechanical properties to the elementary particles by the Higgs mechanism. This Higgs Quantum Space (HQS) thus governs the inertial motion of matter-energy and is locally their ultimate reference for rest and for motions. On the other hand, mo-tion with respect to the local HQS and not relative motion is the origin of all the effects of velocity on matter, on light and on clocks. In previous works, the author has shown that the HQS, moving round the astronomical bodies according to a Keplerian velocity field (GM/r)1/2 e∅, consistent with the local astronomical motions, accurately creates the observed gravitational dynamics and gives rise to all the observed effects of the gravitational fields on light and on clocks. The absence of the solar gravitational slowing on the GPS clocks and the absence of light anisotropy with respect to earth are both the signature of this HQS dynamics. In their orbital motion round the galactic center, the stars carry with them their Keplerian velocity fields. The present work shows that, due to the effects of this orbital velocity on the symmetry of the polarized star Keplerian velocity fields, the collective velocity field, created by them, does not fall with distance as the Keplerian profile (r-1/2 ). Depending on the distribution of the matter density, the velocity of the HQS and the stars can even increase with r. The non-Keplerian rotation of the galaxies thus is an intrinsic feature of the HQS dynamics gravitational mechanism, created without the need of dark matter.

Influence of Infinitesimal Neglected Effects by Current Theory of Gravitation and Experiments on the Stability of the Universe

From the hypotheses compatible with microphysics theory, this paper establishes a new theoretical model of static universal gravitation and deduces new formula of the theory of universal gravitation. In a first order approximation, the new formula shows the inverse-square law consistent with Newton formula, which would indicate that the new theory is consistent with the experimental results that can be reasonably explained by the current theory of gravitation. The parameters and higher order terms among the coefficients of this paper reveal the numerous infinitesimal neglected effects by current theory and experiments. In the first order approximation, the meanings of the physical parameters included in coefficients are analyzed and the infinitesimal neglected effects are applied in the study of the stability of the universe, which overcomes the difficulty of singularity in the cosmology of Newton, Einstein, etc., and concludes that the boundary of universe is unlimited, without any need of the hypothesis that the universe starts off with the big bang. Therefore, this paper establishes a harmonious and ingenious relationship between microphysics and macrophysics theories. In addition, through the analysis of the formula derived from the theory of this paper, it is found that: in general, the gravitational constant is not always a constant in the gravitation formula requiring high precision;from the perspective of the interaction of field quantum, the acting force may not be equal to counter-acting force under the interaction of indirect contact;the gravity process is an exothermic process;in the gravitational process, annihilation effects may exist amongst gravitons;reciprocal translation may exist amongst fundamental forces.

Gravitational constant in f(R) theories of gravity with non-minimal coupling between matter and geometry

We study the effect of the non-minimal coupling between matter and geometry on the gravitational constant in the context of f(R) theories of gravity on cosmic scales. For a class of f(R) models,the result shows that the value of the gravitational constant not only changes over time but also has the dampened oscillation behavior.Compared with the result of the standard ACDM model, the consequence suggests that the coupling between matter and geometry should be weak.

A NON-DUALISTIC UNIFIED FIELD THEORY OF GRAVITATION,ELECTROMAGNETISM AND SPIN

The wisdom of classicalunified field theories in the conceptual framework of Weyl, Eddington, Einstein and Schrodinger has often been doubted and in particular there does not appear to be any empirical reason why the Einstein-Maxwell (E-MJ theory needs to be geometrized. The crux of the matter is, however not whether the E-M theory is aesthetically satisfactory but whether it answers all the modern questions within the classical context. In particular, the E-M theory does not provide a classical platform from which the Dirac equation can be derived in the way Schrodinger's equation is derived from classical mechanics via the energy equation and the Correspondence Principle. The present paper presents a non-dualistic unified field theory (UFT) in the said conceptual framework as propounded by M. A. Tonnelat. By allowing the metric form ds2=g,dx dx and the non-degenerate two-form F=(1/2t)rdx dx to enter symmetrically into the theory we obtain a UFT which contains Einstein's General Relativity and the Born-Infeld electrodynamics as special cases. Above all, it is shown that the Dirac equation describing the electron in an 'external' gravito-electromagnetic field can be derived from the non-dualistic Einstein equation by a simple factorization if the Correspondence Principle is assumed.

Bianchi Type-IX Magnetized Dark Energy Model in Saez-Ballester Theory of Gravitation

The Bianchi type-IX cosmological model with variable ω has been studied in the scalar tensor theory of gravitation proposed by Saez and Ballester [Phys. Lett. A 113: 467, 1985] in the presence and absence of magnetic field of energy densityρb. A special law of variation of Hubble’s parameter proposed by Berman [Nuovo Cimento 74 B, 182, 1983] has been used to solve the field equations. The physical and kinematical properties of the model are also discussed.

Precise Measurements of the Gravitational Constant: Revaluation by the Information Approach

The gravitational constant discovered by Newton is still measured with a relative uncertainty that is several orders of magnitude larger than the relative uncertainty of other fundamental constants. Numerous methods are used to measure it. This article discusses the information-oriented approach for analyzing the achievable relative measurement uncertainty, in which the magnitude of the gravitational constant can be considered as plausible. A comparison is made and the advantages and disadvantages of various methods are discussed in terms of the possibility of achieving higher accuracy using a new metric called comparative uncertainty, which was proposed by Brillouin.