Solution to the Cosmological Constant Problem by Gauge Theory of Gravity

Based on geometry picture of gravitational gauge theory, the cosmological constant is determined theoreti-cally. The cosmological constant is related to the average energy density of gravitational gauge field. Because the energydensity of gravitational gauge field is negative, the cosmological constant is positive, which generates repulsive force onstars to make the expansion rate of the Universe accelerated. A rough estimation of it gives out its magnitude of theorder of about 10-52m-2, which is well consistent with experimental results.     

Solution to the Cosmological Constant Problem by Gauge Theory of Gravity

Based on geometry picture of gravitational gauge theory, the cosmological constant is determined theoreti-cally. The cosmological constant is related to the average energy density of gravitational gauge field. Because the energy density of gravltatlona] gauge field is negative, the cosmological constant is positive, which generates repulasive force on stars to make the expansion rate of the Universe accelerated. A rough estimation of it gives out its magnitude of the order of about 10^52m^-2, which is well consistent with experimental results.     

A broken-symmetry theory of gravity

Quantum effects at the beginning of the universe suggest the variability of the cosmical constant and the effective gravitational constant. These variations may be incorporated into the theory of gravity in a natural way by proposing a longrange complex scalar field similar to the massless Higgs scalar field. On this basis a broken-symmetry theory of gravity has been proposed. The WKB expansion of the complex scalar field helps us to relate the effective gravitational constant to the usual gravitational constant. The proposed theory of gravity has been applied to a homogeneous and isotropic cosmological model to study the quantum effects near the beginning of the universe.     

含物质纯重力场部分贡献的静态和稳态重力场研究

给出了包含重力场贡献在内具有宇宙因子项最普遍形式的重力场方程为Rμν-gμνR/2+λgμν=8πG(T(Ⅰ)μν+T(Ⅱ)μν)/c4，这里λ为Einstein宇宙常数，Ｔ（Ⅰ）μν，Ｔ（Ⅱ）μν分别代表物质纯物质部分和纯重力场部分的能量-动量张量.物质纯重力场部分的能量-动量张量表述为T(Ⅱ)μν=(DμρＤρν-gμνＤαβＤαβ/4)/4πG，式中Dμν的定义为Ｄμν＝ωμ／xν-ων／xμ，ωμ≡-c2gμ0/g00.并用重力场贡献在内最普遍形式的重力场方程分别研究了几个大家所熟悉的静态和稳态重力场，像带有Einstein宇宙因子λ项球对称纯物质球外部静态度规、静态荷电球外部度规、匀速转动星体外部度规及理想纯物质星体内部静态平衡等,并进行了讨论. 关键词： 能量动量张量 重力场方程 静态重力场 稳态重力场     

The hyperon coupling constants and the surface gravitational redshift of massive neutron stars

With relativistic mean field theory we examine effect of hyperon coupling constants of hyperon Ξ on the surface gravitational redshift of the massive neutron star (NS) PSR J1614-2230 and NS PSR J0348+0432 as the potential well depth of hyperon Ξ is fixed. We find that the mass and radius of a NS increase with the increase of the coupling constant of hyperon Ξ. With the increase of the coupling constant of the hyperon Ξ, the surface gravitational redshift will decrease for a same NS mass but will increase for a same NS radius. The surface gravitational redshift of the more massive NS PSR J0348+0432 decreases by more than that of the less massive NS PSR J1614-2230. We also find that the value range of the surface gravitational redshift of NS will become narrower with the increase of the coupling constant of hyperon Ξ. The greater the NS mass, the greater the influence of the coupling constant of hyperon Ξ on the value range of the surface gravitational redshift of the NS.     

On the sources of static plane symmetric vacuum space-times

The sources of static vacuum plane space-times with reflection symmetry are considered. It is argued that the counterpart of the Einstein theory to the gravitational field of a massive Newtonian plane should be described by the Rindler solution, which represents also a uniform gravitational field, and the test particles moving in which have constant accelerations.     

Localization of gravitational energy

In the general relativity theory gravitational energy-momentum density is usually described by a pseudo-tensor with strange transformation properties so that one does not have localization of gravitational energy. It is proposed to set up a gravitational energy-momentum density tensor having a unique form in a given coordinate system by making use of a bimetric formalism. Two versions are considered: (1) a bimetric theory with a flat-space background metric which retains the physics of the general relativity theory and (2) one with a background corresponding to a space of constant curvature which introduces modifications into general relativity under certain conditions. The gravitational energy density in the case of the Schwarzschild solution is obtained.     

Large numbers hypothesis. IV. The cosmological constant and quantum physics

In standard physics quantum field theory is based on a flat vacuum space-time. This quantum field theory predicts a nonzero cosmological constant. Hence the gravitational field equations do not admit a flat vacuum space-time. This dilemma is resolved using the units covariant gravitational field equations. This paper shows that the field equations admit a flat vacuum space-time with nonzero cosmological constant if and only if the canonical LNH is valid. This allows an interpretation of the LNH phenomena in terms of a time-dependent vacuum state. If this is correct then the cosmological constant must be positive.     

Gravitational waves in the general theory of relativity

The methods and capabilities of the invariant theory of gravitational radiation derived previously are demonstrated for an exact solution of the Kaigorodov type III. Analysis of this solution shows that it describes gravitational radiation with sources.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 11, pp. 121–125, November, 1969.In conclusion, we thank V. I. Rodichev for constant interest in this study.     

First Order Approximation of the 5-dimensional Projective Unified Field Theory

The new version of a 5-dimensional Projective Unified Field Theory is presented up to the first order approximation with respect to the gravitational constant and referring to nonrelativistic velocities. Since exact solutions of this theory can only be found for exceptional cases, this approximation procedure provides a practicable approach to physical applications of the theory.     

Outline of a classical theory of quantum physics and gravitation

It is argued that in the manner in which the Galilean-Newtonian physics may be said to have explained the Ptolemaic-Copernican theories in terms which have since been called classical, so also Milner's theories of the structure of matter may be said to explain present day quantum and relativistic theory. In both cases the former employ the concept of force and the latter, by contrast, are geometrical theories. Milner envisaged space as being stressed, whereas Einstein thought of it as strained. Development of Milner's theory from criticisms and suggestions made by Kilmister has taken it further into the realms of quantum and gravitational physics, where it is found to give a more physically comprehensible explanation of the phenomena. Further, it shows why present day quantum theory is cast in a statistical form. The theory is supported by many predictions such as the ratio of Planck's constant to the mass of the electron, the value of the fine structure constant and reason for apparent variations in past measurements, the magnetic moment of the electron and proton of the stable particles such as the neutron Λ and Σ together with the kaon, and a relation between the universal gravitational constant and Hubble's constant—all within published experimental accuracy. The latest results to be accounted for by the theory are the masses of the newly discovered ψ particles and confirmation of the value of the decay of Newton's gravitational constant obtained from lunar measurements. While this paper is being typed, new particles are rapidly being discovered—the latest being a neutral ψ particle. A short Appendix discusses the significance of these.     

Can quantum gravitational forces stop gravitational collapse?

We consider, in lowest order of the gravitational coupling constant G, the gravitational potential between two neutrons. As we have previously pointed out [1],the quantum (including spin) contributions to the gravitational field dominate for distances smaller than the Compton wavelength of the neutron. At such distances the gravitational force between two neutrons may be repulsive. In particular, the gravitational forces which are analogous to the familiar Darwin and Fermi forces of quantum electrodynamics are capable of stopping gravitational collapse. Our discussion is within the framework of Einstein's theory, but on a microscopic level. We conclude that gravitational collapse may be halted without the necessity of extending Einstein's theory à la Cartan or otherwise.     

Strong gravitational waves in semiclosed electromagnetic universes. Statement and analysis of the problem in terms of the method of spin coefficients

The problem of integration is discussed for a complete system of Newman-Penrose equations for electrovacuum spaces of the general theory of relativity with nonzero cosmological constant. In terms of the method of spin coefficients, we formulate conditions on the electromagnetic and gravitational field variables, which distinguish a special class of Riemann spaces corresponding to strong gravitational waves in semiclosed Universes of Bertotti-Robinson type.Translated from Izvestiya Vysshikh Uchebnykh Zavederiii, Fizika, No. 11, pp. 74–78, November, 1987.     

Hamiltonian formulation of the theory of interacting gravitational and electron fields

The action which describes the interaction of gravitational and electron fields is expressed in canonical form. In addition to general covariance, it exhibits the local Lorentz invariance associated with four-dimensional rotations of the local orthonormal frames. The corresponding Hamiltonian constraints are derived and their (Dirac) bracket relations given. The derivative coupling of the gravitational tetrad and spinor fields is not present in the Hamiltonian, but rather in the unusual bracket relations of the field variables in the theory. If the timelike leg of the tetrad field is fixed to be normal to the x^o = constant hyper-surfaces (“time gauge”) the derivative coupling drops from the theory in the sense that the relation between the gravitational velocities and momenta is the same as when the spinor fields are absent.     

Inflationary Brans-Dicke universe andG

In a recent paper, Mathiazhagan and Johri reduced the field equations for an isotropic, homogeneous, and almost flat universe with a constant vacuum-energy density by Brans-Dicke theory to a pair of coupled differential equations. They also obtained a particular solution of these equations. Further, they used this particular solution of the equations to estimate the value of the gravitational constant. Here we obtain the complete set of solutions of the above-mentioned coupled differential equations and improved the estimate of Mathiazhagan and Johri of the gravitational constant.     

Short distance freedom of quantum gravity

Fourth order derivative gravity in 3+1$3+1$ dimensions is perturbatively renormalizable and is shown to describe a unitary theory of gravitons in a limited coupling parameter space. The running gravitational constant which includes graviton contribution is computed. Generically, gravitational Newton?s constant vanishes at short distances in this perturbatively renormalizable and unitary theory.     

On Some Processes of Quantum Gravitation (Radiative Corrections)

Within the framework of the quantum theory of interactions of nonpoint (smeared out) particles [1], the radiative corrections due to gravitational interactions are examined. The gravitational masses are calculated for a photon, a graviton, and some other particles together with the renormalized gravitational interaction constant K(m) depending on the interacting particle mass m. The approximate character of the equivalence principle is confirmed.     

A comparison of results of various theories for four fundamental constants of physics

A comparison is made of theoretical values of various authors for the fine structure constant, for the proton-electron and muon-electron mass ratios, and for the gravitational constant. It is shown that a lattice ether theory developed by Aspden gives the best overall agreement with experiment.     

Higgs field and a new scalar-tensor theory of gravity

The combination of Brans and Dicke's idea of a variable gravitational constant with the Higgs-field mechanism of elementary particle physics results in a new theory of gravity. Einstein's theory is realized after symmetry breaking in the neighborhood of the Higgs-fleld ground state.