I'm physicist. My field is theoretical and computational physics and astrophysics, including different areas: classical mechanics (three body problem), symmetries and conservation laws, quantization, field theory, theory of gravity, compact astrophysical objects, cosmology, hierarchy in astrophysics
In this paper, we discuss in brief some basic issues of quantum space gravimetry, related to stan... more In this paper, we discuss in brief some basic issues of quantum space gravimetry, related to standard approach of geodesy which is based on the Newton model of gravity and Euclidean geometry. We emphasize the need to apply relativistic gravity in practical high-precision geodesy. Here we do not intend to solve the existing hard experimental and theoretical problems, being essential for the topic: development of quantum gravity, physics of dark matter and dark energy, novel physical principles of extended general relativity, in particular, a nonlinear superposition principle in general relativity and its extensions, and so on. Rather, we point out the fundamental unsolved problems, which are substantial for quantum space gravimetry and future practical high-precision geodesy. We outline the possible ways for their study and decision. Thus, to some extend, the present paper is a program for further developments, not a presentation of the fnal solutions. Our goal is to warn correspondi...
In this paper, we discuss in brief some basic issues of quantum space gravimetry, related to stan... more In this paper, we discuss in brief some basic issues of quantum space gravimetry, related to standard approach of geodesy which is based on the Newton model of gravity and Euclidean geometry. We emphasize the need to apply relativistic gravity in practical high-precision geodesy. Here we do not intend to solve the existing hard experimental and theoretical problems, being essential for the topic: development of quantum gravity, physics of dark matter and dark energy, novel physical principles of extended general relativity, in particular, a nonlinear superposition principle in general relativity and its extensions, and so on. Rather, we point out the fundamental unsolved problems, which are substantial for quantum space gravimetry and future practical high-precision geodesy. We outline the possible ways for their study and decision. Thus, to some extend, the present paper is a program for further developments, not a presentation of the fnal solutions. Our goal is to warn correspondi...
Using an effective one body approach we describe in detail gravitational waves from classical thr... more Using an effective one body approach we describe in detail gravitational waves from classical three body problem on a non-rotating straight line and derive their basic physical characteristics. Special attention is paid to the irregular motions of such systems and to the significance of double and triple collisions. The conclusive role of the collinear solutions is also discussed in short. It is shown that the residuals may contain information about irregular motion of the source of gravitational waves.
We are discussing the possibility to find a proper unique conditions for an experimental study of... more We are discussing the possibility to find a proper unique conditions for an experimental study of the Schr\"odinger quantization problem in the neutron stars physics. A simple toy model for physically different quantizations is formulated and a possible physical consequences are derived.
We present a class of simple scalar-tensor models of gravity with one scalar field (dilaton Φ) an... more We present a class of simple scalar-tensor models of gravity with one scalar field (dilaton Φ) and only one unknown function (cosmological potential U(Φ)). These models might be considered as a stringy inspired ones with broken SUSY. They have the following basic properties: 1) Positive dilaton mass, m_Φ, and positive cosmological constant Λ, define two extremely different scales. The models under consideration are consistent with the known experimental facts if m_Φ > 10^-3 eV and Λ=Λ^obs∼ 10^-56 cm^-2. 2) Einstein week equivalence principle is strictly satisfied and extended to scalar-tensor theories of gravity using a novel form of principle of "constancy of fundamental constants". 3) The dilaton plays simultaneously role of inflation field and quintessence field and yields a sequential hyper-inflation with graceful exit to asymptotic de Sitter space-time which is an attractor, and is approached as (-√(3Λ^obs) ct/2). The time duration of inflation is Δ t_infl∼ m_Φ^-1....
It is shown that the recently proposed interpretation of the transposed equi-affine theory of gra... more It is shown that the recently proposed interpretation of the transposed equi-affine theory of gravity as a theory with variable Plank "constant" is inconsistent with basic solar system gravitational experiments.
We solve exactly the Regge-Wheeler equation for axial perturbations of the Schwarzschild metric i... more We solve exactly the Regge-Wheeler equation for axial perturbations of the Schwarzschild metric in the black hole interior in terms of Heun functions and give a description of the spectrum and the eigenfunctions of the interior problem. The phenomenon of attraction and repulsion of the discrete eigenvalues of gravitational waves is discovered.
The Regge-Wheeler equation describes axial perturbations of Schwarzschild metric in linear approx... more The Regge-Wheeler equation describes axial perturbations of Schwarzschild metric in linear approximation. Teukolsky Master Equation describes perturbations of Kerr metric in the same approximation. We present here unified description of all classes of exact solutions to these equations in terms of the confluent Heun's functions. Special attention is paid to the polynomial solutions, which yield novel applications of Teukolsky Master Equation for description of relativistic jets and astrophysical explosions.
We present solution of the equations for relativistic static spherically symmetric stars (SSSS) i... more We present solution of the equations for relativistic static spherically symmetric stars (SSSS) in the model of minimal dilatonic gravity (MDG) using the polytropic equation of state. A polytropic equation of state, which has a good fitting with a more realistic one, is used. Results are obtained for all variables of a single neutron star in the model of MDG. The maximum mass about two solar masses is in accordance with the latest observations of pulsars. Several new effects are observed for the variables related with the dilaton Φ and the cosmological constant Λ. The mass-radius relation is also obtained. Special attention is paid to the behavior of the quantities which describe the effects analogous to those of dark energy and dark matter in MDG. The results of the present paper confirm the conclusion that the dilaton Φ is able to play simultaneously the role of dark energy and dark matter.
We develop the general theory of stars in Saa's model of gravity with propagating torsion and... more We develop the general theory of stars in Saa's model of gravity with propagating torsion and study the basic stationary state of neutron star. Our numerical results show that the torsion force decreases the role of the gravity in the star configuration leading to significant changes in the neutron star masses depending on the equation of state of star matter. The inconsistency of the Saa's model with Roll-Krotkov-Dicke and Braginsky-Panov experiments is discussed.
We study the relation between Minimal Dilatonic Gravity (MDG) and f(R) theories of gravity and es... more We study the relation between Minimal Dilatonic Gravity (MDG) and f(R) theories of gravity and establish strict conditions for their global equivalence. Such equivalence takes place only for a certain class of cosmological potentials, dubbed here withholding potentials, since they prevent change of the sign of dilaton Φ. The withholding property ensures the attractive character of gravity, as well as absence of ghosts and a tachyon in the gravi-dilaton sector and yields certain asymptotic of the admissible functions f(R). Large classes of withholding cosmological potentials and functions f(R) are found and described in detail. It is shown that the popular choices of f(R) functions are not withholding ones. The particle content of the gravi-dilaton sector is found using perturbation theory around de Sitter vacuum of MDG. The graviton remains massless, since it obeys conformal invariant field equation in the de Sitter space-time. The R/6 term in the conformal invariant wave operator i...
We consider for the first time the solutions of Klein-Gordon equation in gravitational field of a... more We consider for the first time the solutions of Klein-Gordon equation in gravitational field of a massive point source in GR. We examine numerically the basic bounded quantum state and the next few states in the discrete spectrum for different values of the orbital momentum. A novel feature of the solutions under consideration is the essential dependence if their physical properties on the gravitational mass defect of the point source, even not introduced up to recently. It yields a repulsion or an attraction of the quantum levels up to their quasi-crossing.
The proper understanding of the electromagnetic counterpart of gravity-waves emitters is of serio... more The proper understanding of the electromagnetic counterpart of gravity-waves emitters is of serious interest to the multimessenger astronomy. In this article, we study the numerical stability of the quasinormal modes (QNM) and quasibound modes (QBM) obtained as solutions of the Teukolsky Angular Equation and the Teukolsky Radial Equation with appropriate boundary conditions. We use the epsilon-method for the system featuring the confluent Heun functions to study the stability of the spectra with respect to changes in the radial variable. We find that the QNM and QBM are stable in certain regions of the complex plane, just as expected, while the third "spurious" spectrum was found to be numerically unstable and thus unphysical. This analysis shows the importance of understanding the numerical results in the framework of the theory of the confluent Heun functions, in order to be able to distinguish the physical spectra from the numerical artifacts.
The Heun functions have wide application in modern physics and are expected to succeed the hyperg... more The Heun functions have wide application in modern physics and are expected to succeed the hypergeometrical functions in the physical problems of the 21st century. The numerical work with those functions, however, is complicated and requires filling the gaps in the theory of the Heun functions and also, creating new algorithms able to work with them efficiently. We propose a new algorithm for solving a system of two nonlinear transcendental equations with two complex variables based on the M\"uller algorithm. The new algorithm is particularly useful in systems featuring the Heun functions and for them, the new algorithm gives distinctly better results than Newton's and Broyden's methods. As an example for its application in physics, the new algorithm was used to find the quasi-normal modes (QNM) of Schwarzschild black hole described by the Regge-Wheeler equation. The numerical results obtained by our method are compared with the already published QNM frequencies and are...
We study a new minimal scalar-tensor model of gravity with Brans-Dicke factor ω(Φ)≡ 0 and cosmolo... more We study a new minimal scalar-tensor model of gravity with Brans-Dicke factor ω(Φ)≡ 0 and cosmological factor Π(Φ). The constraints on Π(Φ) from known gravitational experiments are derived. We show that almost any time evolution of the scale factor in a homogeneous isotropic Universe can be obtained via properly chosen Π(Φ) and discuss the general properties of models of this type.
In the framework of a model of minimal of dilatonic gravity (MDG) with cosmological potential we ... more In the framework of a model of minimal of dilatonic gravity (MDG) with cosmological potential we consider: the relations of MDG with nonlinear gravity and string theory; natural cosmological units, defined by cosmological constant; the properties of cosmological factor, derived from solar system and Earth-surface gravitational experiments; universal anty-gravitational interactions, induced by positive cosmological constant and by Nordtved effect; a new formulation of cosmological constant problem using the ratio of introduced cosmological action and Planck constant ∼ 10 ^122;qualitative analysis of this huge number based on classical action of effective Bohr hydrogen atoms; inverse cosmological problem: to find cosmological potential which yields given evolution of the RW Universe; and comment other general properties of MDG.
In this paper, we discuss in brief some basic issues of quantum space gravimetry, related to stan... more In this paper, we discuss in brief some basic issues of quantum space gravimetry, related to standard approach of geodesy which is based on the Newton model of gravity and Euclidean geometry. We emphasize the need to apply relativistic gravity in practical high-precision geodesy. Here we do not intend to solve the existing hard experimental and theoretical problems, being essential for the topic: development of quantum gravity, physics of dark matter and dark energy, novel physical principles of extended general relativity, in particular, a nonlinear superposition principle in general relativity and its extensions, and so on. Rather, we point out the fundamental unsolved problems, which are substantial for quantum space gravimetry and future practical high-precision geodesy. We outline the possible ways for their study and decision. Thus, to some extend, the present paper is a program for further developments, not a presentation of the fnal solutions. Our goal is to warn correspondi...
In this paper, we discuss in brief some basic issues of quantum space gravimetry, related to stan... more In this paper, we discuss in brief some basic issues of quantum space gravimetry, related to standard approach of geodesy which is based on the Newton model of gravity and Euclidean geometry. We emphasize the need to apply relativistic gravity in practical high-precision geodesy. Here we do not intend to solve the existing hard experimental and theoretical problems, being essential for the topic: development of quantum gravity, physics of dark matter and dark energy, novel physical principles of extended general relativity, in particular, a nonlinear superposition principle in general relativity and its extensions, and so on. Rather, we point out the fundamental unsolved problems, which are substantial for quantum space gravimetry and future practical high-precision geodesy. We outline the possible ways for their study and decision. Thus, to some extend, the present paper is a program for further developments, not a presentation of the fnal solutions. Our goal is to warn correspondi...
Using an effective one body approach we describe in detail gravitational waves from classical thr... more Using an effective one body approach we describe in detail gravitational waves from classical three body problem on a non-rotating straight line and derive their basic physical characteristics. Special attention is paid to the irregular motions of such systems and to the significance of double and triple collisions. The conclusive role of the collinear solutions is also discussed in short. It is shown that the residuals may contain information about irregular motion of the source of gravitational waves.
We are discussing the possibility to find a proper unique conditions for an experimental study of... more We are discussing the possibility to find a proper unique conditions for an experimental study of the Schr\"odinger quantization problem in the neutron stars physics. A simple toy model for physically different quantizations is formulated and a possible physical consequences are derived.
We present a class of simple scalar-tensor models of gravity with one scalar field (dilaton Φ) an... more We present a class of simple scalar-tensor models of gravity with one scalar field (dilaton Φ) and only one unknown function (cosmological potential U(Φ)). These models might be considered as a stringy inspired ones with broken SUSY. They have the following basic properties: 1) Positive dilaton mass, m_Φ, and positive cosmological constant Λ, define two extremely different scales. The models under consideration are consistent with the known experimental facts if m_Φ > 10^-3 eV and Λ=Λ^obs∼ 10^-56 cm^-2. 2) Einstein week equivalence principle is strictly satisfied and extended to scalar-tensor theories of gravity using a novel form of principle of "constancy of fundamental constants". 3) The dilaton plays simultaneously role of inflation field and quintessence field and yields a sequential hyper-inflation with graceful exit to asymptotic de Sitter space-time which is an attractor, and is approached as (-√(3Λ^obs) ct/2). The time duration of inflation is Δ t_infl∼ m_Φ^-1....
It is shown that the recently proposed interpretation of the transposed equi-affine theory of gra... more It is shown that the recently proposed interpretation of the transposed equi-affine theory of gravity as a theory with variable Plank "constant" is inconsistent with basic solar system gravitational experiments.
We solve exactly the Regge-Wheeler equation for axial perturbations of the Schwarzschild metric i... more We solve exactly the Regge-Wheeler equation for axial perturbations of the Schwarzschild metric in the black hole interior in terms of Heun functions and give a description of the spectrum and the eigenfunctions of the interior problem. The phenomenon of attraction and repulsion of the discrete eigenvalues of gravitational waves is discovered.
The Regge-Wheeler equation describes axial perturbations of Schwarzschild metric in linear approx... more The Regge-Wheeler equation describes axial perturbations of Schwarzschild metric in linear approximation. Teukolsky Master Equation describes perturbations of Kerr metric in the same approximation. We present here unified description of all classes of exact solutions to these equations in terms of the confluent Heun's functions. Special attention is paid to the polynomial solutions, which yield novel applications of Teukolsky Master Equation for description of relativistic jets and astrophysical explosions.
We present solution of the equations for relativistic static spherically symmetric stars (SSSS) i... more We present solution of the equations for relativistic static spherically symmetric stars (SSSS) in the model of minimal dilatonic gravity (MDG) using the polytropic equation of state. A polytropic equation of state, which has a good fitting with a more realistic one, is used. Results are obtained for all variables of a single neutron star in the model of MDG. The maximum mass about two solar masses is in accordance with the latest observations of pulsars. Several new effects are observed for the variables related with the dilaton Φ and the cosmological constant Λ. The mass-radius relation is also obtained. Special attention is paid to the behavior of the quantities which describe the effects analogous to those of dark energy and dark matter in MDG. The results of the present paper confirm the conclusion that the dilaton Φ is able to play simultaneously the role of dark energy and dark matter.
We develop the general theory of stars in Saa's model of gravity with propagating torsion and... more We develop the general theory of stars in Saa's model of gravity with propagating torsion and study the basic stationary state of neutron star. Our numerical results show that the torsion force decreases the role of the gravity in the star configuration leading to significant changes in the neutron star masses depending on the equation of state of star matter. The inconsistency of the Saa's model with Roll-Krotkov-Dicke and Braginsky-Panov experiments is discussed.
We study the relation between Minimal Dilatonic Gravity (MDG) and f(R) theories of gravity and es... more We study the relation between Minimal Dilatonic Gravity (MDG) and f(R) theories of gravity and establish strict conditions for their global equivalence. Such equivalence takes place only for a certain class of cosmological potentials, dubbed here withholding potentials, since they prevent change of the sign of dilaton Φ. The withholding property ensures the attractive character of gravity, as well as absence of ghosts and a tachyon in the gravi-dilaton sector and yields certain asymptotic of the admissible functions f(R). Large classes of withholding cosmological potentials and functions f(R) are found and described in detail. It is shown that the popular choices of f(R) functions are not withholding ones. The particle content of the gravi-dilaton sector is found using perturbation theory around de Sitter vacuum of MDG. The graviton remains massless, since it obeys conformal invariant field equation in the de Sitter space-time. The R/6 term in the conformal invariant wave operator i...
We consider for the first time the solutions of Klein-Gordon equation in gravitational field of a... more We consider for the first time the solutions of Klein-Gordon equation in gravitational field of a massive point source in GR. We examine numerically the basic bounded quantum state and the next few states in the discrete spectrum for different values of the orbital momentum. A novel feature of the solutions under consideration is the essential dependence if their physical properties on the gravitational mass defect of the point source, even not introduced up to recently. It yields a repulsion or an attraction of the quantum levels up to their quasi-crossing.
The proper understanding of the electromagnetic counterpart of gravity-waves emitters is of serio... more The proper understanding of the electromagnetic counterpart of gravity-waves emitters is of serious interest to the multimessenger astronomy. In this article, we study the numerical stability of the quasinormal modes (QNM) and quasibound modes (QBM) obtained as solutions of the Teukolsky Angular Equation and the Teukolsky Radial Equation with appropriate boundary conditions. We use the epsilon-method for the system featuring the confluent Heun functions to study the stability of the spectra with respect to changes in the radial variable. We find that the QNM and QBM are stable in certain regions of the complex plane, just as expected, while the third "spurious" spectrum was found to be numerically unstable and thus unphysical. This analysis shows the importance of understanding the numerical results in the framework of the theory of the confluent Heun functions, in order to be able to distinguish the physical spectra from the numerical artifacts.
The Heun functions have wide application in modern physics and are expected to succeed the hyperg... more The Heun functions have wide application in modern physics and are expected to succeed the hypergeometrical functions in the physical problems of the 21st century. The numerical work with those functions, however, is complicated and requires filling the gaps in the theory of the Heun functions and also, creating new algorithms able to work with them efficiently. We propose a new algorithm for solving a system of two nonlinear transcendental equations with two complex variables based on the M\"uller algorithm. The new algorithm is particularly useful in systems featuring the Heun functions and for them, the new algorithm gives distinctly better results than Newton's and Broyden's methods. As an example for its application in physics, the new algorithm was used to find the quasi-normal modes (QNM) of Schwarzschild black hole described by the Regge-Wheeler equation. The numerical results obtained by our method are compared with the already published QNM frequencies and are...
We study a new minimal scalar-tensor model of gravity with Brans-Dicke factor ω(Φ)≡ 0 and cosmolo... more We study a new minimal scalar-tensor model of gravity with Brans-Dicke factor ω(Φ)≡ 0 and cosmological factor Π(Φ). The constraints on Π(Φ) from known gravitational experiments are derived. We show that almost any time evolution of the scale factor in a homogeneous isotropic Universe can be obtained via properly chosen Π(Φ) and discuss the general properties of models of this type.
In the framework of a model of minimal of dilatonic gravity (MDG) with cosmological potential we ... more In the framework of a model of minimal of dilatonic gravity (MDG) with cosmological potential we consider: the relations of MDG with nonlinear gravity and string theory; natural cosmological units, defined by cosmological constant; the properties of cosmological factor, derived from solar system and Earth-surface gravitational experiments; universal anty-gravitational interactions, induced by positive cosmological constant and by Nordtved effect; a new formulation of cosmological constant problem using the ratio of introduced cosmological action and Planck constant ∼ 10 ^122;qualitative analysis of this huge number based on classical action of effective Bohr hydrogen atoms; inverse cosmological problem: to find cosmological potential which yields given evolution of the RW Universe; and comment other general properties of MDG.
In this short paper we consider in brief some basic problems of quantum space gravimetry. Nowaday... more In this short paper we consider in brief some basic problems of quantum space gravimetry. Nowadays, the theory of gravity and its experimental verifications are under close scrutiny. The main reasons are:
Uploads
Papers by Plamen Fiziev