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S. M. Kozyrev

Publications and source records attributed to S. M. Kozyrev.

17 recordsLinked to original sources

Klein-Gordon equation for a particle in brane model

Brane model of universe is considered for free particle. Conservation laws on the brane are obtained using the symmetry properties of the brane. Equation of motion is derived for a particle using variation principle from these conservation laws. This equation includes terms accounting the variation of brane radius. Its solution is obtained at some approximations and dispersion relation for a particle is derived.

gr-qc

Classes of exact static spheroidal Einstein-Maxwell solutions

In this paper we study the spheroidal cases of static charged fluid configurations in general relativity. We consider the effect of the anisotropic stresses of electromagnetic field on the shape of static charged self-graviting objects. It is shown that electromagnetic fields can have significant effect on the structure and properties of self-graviting objects.

gr-qc

New static spheroidal solution in Jordan-Brands-Dicke theory

The static spheroidal solutions of Jordan-Brands-Dicke theory (JBD) are studied. We consider the effect of the anisotropic stresses of scalar field on the shape of JBD self-graviting objects. It is shown that scalar fields can have significant effect on the structure and properties of self-graviting objects. In contrast with general relativity in JBD theory there are nonflat static spheroidal solutions.

gr-qc

Curious interior solutions of general relativity

In this article, we provide a discussion on a composite class of exact static spherically symmetric vacuum solutions of Einstein's equations. We construct the composite solution of Einstein field equation by match the interior vacuum metric in Schwarzschild original gauge, to the exterior vacuum metric in isotropic gauge, at a junction surface. This approach allows us to associate rigorously with both gauges as a same "space", which is a unique differentiable manifold M^4

gr-qc

The Heckmann's wormholes in Jordan-Brans-Dicke gravity

A simple Heckmann's vacuum wormhole solution of Jordan-Brans-Dicke gravitation is presented and analysed. It is shown that in contrast with class I Brans solution where the throat radius becomes real when $ω< -4/3$ here it becomes positive when $ω< -1$.

gr-qc

Composite wormholes in vacuum Jordan-Brans-Dicke theory

New classes composite vacuum wormhole solutions of Jordan-Brans-Dicke gravitation is presented and analysed. It is shown that such solution holds for both, a bridge between separated Schwarzschild and Brans Universes and for a bridge connecting two Schwarzschild asymptotically flat regions joined by Brans throat. We have also noticed that there are some new possible candidates for wormhole spacetimes.

gr-qc

"Jordan's Scalar Stars" and Dark Matter

Here we are starting the study of the field equations of relativistic scalar tensor theories in the spherically symmetric gravitational field. In the present article we shall consider as an example only the simplest Jordan-Brans-Dicke (JBD) one. To illustrate the property of the spherically symmetric JBD configuration we exhibit a new representation of the well-known four dimensional solutions. In this model, a suitable segment of Brans solution is chosen for the interior of the object while the outer region consists of a Schwarzschild vacuum. We have constructed "Jordan's scalar stars" model consisting of three parts: a homogeneous inner core with linear equation of state; an envelope of Brans spacetime matching the core and the exterior Schwarzschild spacetime. We have also showed that this toy model can explain the intergalactic effects without the dark matter hypothesis.

gr-qc

Quantum equation of motion for a particle in the field of primordial fluctuations

Brane model of universe is considered for a particle. Conservation laws inside the brane are obtained. Equation of motion is derived for a particle using variation principle from these conservation laws. This equation includes terms accounting the variation of brane topology. Its solution is obtained at some approximations and dispersion relation for a particle is derived.

gr-qc

A D-dimensional Heckmann-like solution of Jordan-Brans-Dicke theory

In this short letter we present a some rigorous vacuum solutions of the D-dimensional Jordan-Brans-Dicke field equations. In contrast with the well known Brans-Dicke solutions, to the search of static and spherically symmetric space-time we choose the widespread Hilbert coordinates.

gr-qc

Some questions to experimental gravity

The interpretations of solutions of Einstein field's equations led to the prediction and the observation of physical phenomena which confirm the important role of general relativity, as well as other relativistic theories in physics. In this connection, the following questions are of interest and importance: whether it is possible to solve the gauge problem and of its physical significance, which one of the solutions gives the right description of the observed values, how to clarify the physical meaning of the coordinates which is unknown a priori, and why applying the same physical requirements in different gauge fixing, we obtain different linear approximations. We discuss some of the problems involved and point out several open problems. The paper is written mainly for pedagogical purposes.

gr-qc

Gravitational-Wave Detector Dulkyn

The article deals with the results of the research on the realization of the scientific and technical project Dulkyn for detection of low frequency periodic gravitational radiation from the double relativistic astrophysical objects, done by the Scientific Centre of Gravitational-Wave Research Dulkyn of the Academy of Sciences of the Tatarstan Republic (SC GWR Dulkyn AS RT), and the Federal State Unitary Enterprise and R and D Corporation called State Institute of Applied Optics (FSUE NPO GIPO).

gr-qc

Some aspects of the three dimensional gravity theories with temporal scalar field

The present paper proposes a new explanation for the 3-dimensional Einstein general theory of relativity which is free of contradictions and consistent with usual 4-dimensional physics. We discuss the property of the new gravity theory with temporal scalar field arise in lower-dimensional theories as the reduction of timelike extra dimension. These ideas we continued by using the 3-dimensional analog of Jordan, Brans-Dicke theory with temporal scalar field where space and time are treated in different ways.

gr-qc

Three-dimensional interior solutions from Jordan-Brans-Dicke Theory of Gravity

We study spherically symmetric solutions to the Jordan-Brans-Dicke field equations under the assumption that the space-time may possess an arbitrary number of spatial dimensions. Assuming a perfect fluid with the equation of state, we show that there are static interior nontrivial solutions in three dimensional Jordan-Brans-Dicke gravity theory.

gr-qc

Dark matter an effect of gravitation permeability of material in Jordan, Brance - Dicke theory

Analyzing the static spherically symmetric and rotating ellipsoid solutions in the Newtonian limit of Jordan, Brance - Dicke theory we find the following. In empty space scalar-tensor theories have trivial solution of field equation with constant scalar potential (efficient value of gravitation constant). In this case no celestial-mechanical experiments to reveal a difference between scalar-tensor theories and Einstein theory is not presented possible. However, scalar field, inside the matter, has characteristics like gravitation permeability of material similar electromagnetic permeability of material in Maxwell theories of electromagnetism. Investigation of obtained exact solutions for given functions of a matter distributions in the Newtonian limit of Jordan, Brance - Dicke theory show the efficient value of gravitation constant depends on density of matter, sizes and form of object, as well as on the value of theories coupling constant. That for example led to weakening gravitation force in the central regions of a Galaxies. This assumption constitutes the way to explain observed rotation curves of Galaxies without using cold dark matter.

gr-qc