arXiv subjects

Altair Filippov

Publications and source records attributed to Altair Filippov.

7 recordsLinked to original sources

arXiv2022

Type I Shapovalov wave spacetimes in the Brans-Dicke scalar-tensor theory of gravity

Exact solutions for Shapovalov wave spacetimes of type I in the scalar-tensor theory of gravity of Brans-Dicke are constructed. Shapovalov's wave spacetimes describe gravitational-wave models that allow the separation of wave variables in privileged coordinate systems. In contrast to the general theory of relativity, the vacuum field equations of the Brans-Dicke scalar-tensor theory of gravity lead to exact solutions for type I Shapovalov spaces, which makes it possible to construct observational checks for detecting such wave disturbances. For the models under consideration, equations for the trajectories of test particles are obtained.

gr-qc↗

arXiv2022

Quadratic theory of gravity with a scalar field and type I Shapovalov wave spacetimes

For the quadratic theory of gravity with a scalar field, exact solutions are found for gravitational-wave models in Shapovalov~I~type spacetimes, which do not arise in models of the general theory of relativity. The theory of gravity under consideration can effectively describe the early stages of the dynamics of the universe. Type I Shapovalov spaces are the most general form of gravitational-wave Shapovalov spacetimes, whose metric in privileged coordinate systems depends on three variables, including the wave variable. For Einstein vacuum spacetimes, these wave models degenerate into simpler types. The obtained exact models of gravitational waves in the quadratic theory of gravity can be used to test the realism of such theories of gravity.

gr-qc↗

arXiv2021

Exact models of pure radiation in R^2 gravity for spatially homogeneous Shapovalov spacetimes type II

Presented are exactly integrable models with pure radiation in R^2 gravity with a cosmological constant, related to wave-like Shapovalov spacetimes type II. Spatially homogeneous models of Shapovalov spaces were considered. The obtained solutions belong to spaces of type III according to the Bianchi classification. For the models under consideration, exact solutions of the equations of motion of test particles are obtained in the Hamilton-Jacobi formalism.

gr-qc↗

arXiv2020

Wave-like spatially homogeneous models of Stackel spacetimes (3.1) type in the scalar-tensor theory of gravity

All classes of spatially homogeneous space-time models in the generalized scalar-tensor theory of gravity are found that allow the integration of the equations of motion of test particles and the eikonal equation by the method of %complete separation of variables by type (3.1). Three classes of exact solutions are obtained that relate to wave-like spacetime models. The resulting spacetime models are of type IV, VI, and VII according to the Bianchi classification and type N according to Petrov's classification.

gr-qc↗

arXiv2020

Spatially homogeneous conformal Stäckel spacetimes of type (3.1)

In this work, we obtain all spatially homogeneous space-time models related to the intersection of the set of Stäckel spaces of type (2.1) and the set of conformally Stäckel spaces of type (3.1). These models allow a complete separation of variables both in the Hamilton-Jacobi equation for massive test particles and in the eikonal equation for radiation. The models obtained in this work relate to wave-like space-time models. For the found models, solutions of the Einstein equations with the cosmological constant and radiation are obtained. For the obtained solutions, the eikonal equation and the equations of motion of massive test particles in the Hamilton-Jacobi form are integrated.

gr-qc↗

arXiv2020

Spatially homogeneous models of Stäckel spacetimes of type (2.1)

All classes of spatially homogeneous space-time models are found that allow the integration of the equations of motion of test particles and the eikonal equation by the method of complete separation of variables according to type (2.1). Four classes of model data are obtained. The resulting models can be applied in any modified metric theories of gravity. Two of the above models allow solutions of the Einstein equations with a cosmological constant and radiation. For the models of a spatially homogeneous Universe with a cosmological constant and radiation obtained in Einstein's theory of gravity, the Hamilton-Jacobi equations of motion of the test particles and the eikonal equation for radiation are integrated by the method of separation of variables.

gr-qc↗

arXiv2015

The space-time models with dust matter that admit separation of variables in Hamilton-Jacobi equations of a test particle

The characteristics of dust matter in space-time models, admitting the existence of privilege coordinate systems are given, where the single-particle Hamilton-Jacobi equation can be integrated by the method of complete separation of variables. The resulting functional form of the 4-velocity field and energy density of matter for all types of spaces under consideration is presented.

gr-qc↗