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Yu. G. Ignat'ev

Publications and source records attributed to Yu. G. Ignat'ev.

At least 19 recordsLinked to original sources
arXiv2024

Cosmological models based on an asymmetric scalar Higgs doublet with potential interactions between components

Cosmological models based on an asymmetric scalar Higgs doublet (canonical $Φ$ and phantom $ϕ$ fields) with potential interaction between the components are proposed. A qualitative analysis of the corresponding dynamic systems is performed and their transformation properties with respect to similarity transformations of fundamental constants are revealed. Asymptotic behavior of this class of cosmological models near cosmological singularities is investigated. Numerical simulations revealed a number of interesting features of these models, in particular, the possibility of a fairly long ``waiting phase'', during which the Universe is almost Euclidean, as well as the presence of bounce points, in the vicinity of which strong oscillations of scalar potentials occur. Keywords: Asymmetric scalar Higgs doublet, cosmological models, qualitative analysis, asymptotic behavior, waiting phase, bounces.

gr-qc↗
arXiv2024

Cosmological models based on an asymmetric scalar doublet with kinetic coupling of components. I. General properties of the cosmological model

A mathematical model of the Universe evolution, based on asymmetric doublet of classical and phantom dcalar Higgs fields with a kinetic connection between the components, has been constructed and studied. A detailed qualitative analysis was carried out, the properties of the model's symmetry and invarience with respect to the similariry transformations of fundamental constants were proven. The principles of numerical modeling are formulated and an example of numerical modeling of the evolution of the model for a specific set of fundamental constants and initial conditions is given. the asymptotic behavior of the model near cosmological singularities is studied. It is shown that cosmological model near singularities manifests itself as an ideal fluid with an extremelly ripid equation of state. Keywords: cosmological model, phantom and classical scalar fields, kinetic interection, quality analysis, asymptotic behavior, numerrical modeling.

gr-qc↗
arXiv2024

Self-gravitating Higgs field of scalar charge. II. Asymmetric scalar doublet

The self-gravitating Higgs field of a scalar charge is studied for the case of an asymmetric scalar doublet containing, along with a canonical and a phantom component. It is shown that in the zero and first approximation of the smallness of the canonical and phantom scalar charges, the gravitational field of the scalar charge is described by the Schwarzschild-de Sitter metric with a cosmological constant determined by the stable equilibrium point - the vacuum potential of the canonical Higgs field and the zero value of the scalar potential. An equation for the perturbation of the stable value of the potential is obtained and studied, and the asymptotic behavior in the near and far zones is found. The averaging of microscopic oscillations of the scalar field is carried out and it is shown that the sign of the contribution of microscopic oscillations to the macroscopic energy of the scalar field is completely determined by the values of the fundamental constants of the Higgs potential of the asymmetric scalar doublet. Particular attention is paid to the case when the contribution of oscillations to the macroscopic energy and pressure densities is strictly equal to zero. Possible applications of the obtained solutions are discussed. Keywords: scalarly charged black hole, asymmetric scalar doublet, scalar Higgs field, asymptotic behavior, macroscopic characteristics, doublet orientation.

gr-qc↗
arXiv2024

Evolution of spherical perturbations in the cosmological environment of the Higgs scalar field and an ideal scalar charged fluid

A mathematical model of the evolution of spherical perturbations in a cosmological ideal scalar-charged fluid with scalar Higgs interaction is constructed. A closed mathematical model of linear spherical perturbations in a cosmological medium of a scalar-charged ideal fluid with scalar Higgs interaction is formulated. It is shown that spherical perturbations of the Friedmann metric are possible only in the presence of an isotropic fluid. At singular points of the background cosmological model, perturbations of the metric do not occur and perturbations are described by a vacuum-field model. Exact ones at singular points of the cosmological system are obtained and it is shown that in the case of a stable singular point of the cosmological system, perturbations of the scalar field represent traveling waves, and in the case of an unstable singular point, perturbations represent exponentially growing standing waves. Using numerical modeling, the formation of a stratified halo in the form of growing standing waves is shown. Key words: scalar charged plasma, cosmological model, scalar Higgs field, gravitational stability, spherical perturbations.

gr-qc↗
arXiv2024

Evolution of plane perturbations in the cosmological environment of the Higgs scalar field and an ideal scalar charged fluid

A phenomenological model of an ideal fluid with a scalar charge is formulated, on the basis of which a model with a neutral fluid and a vacuum-field model with rules of transition between them are constructed. A qualitative analysis of the obtained dynamic systems is carried out and numerical cosmological models based on these systems are constructed. A mathematical model of plane longitudinal scalar-gravitational perturbations of the Friedmann ideal charged fluid with Higgs interaction is formulated. It is shown that in the absence of fluid, i.e., in the vacuum-field model, gravitational perturbations do not arise. Perturbations of the scalar field are possible only in those cases when in the unperturbed state the cosmological system is at singular points. For these cases, exact solutions of the field equation are found, expressed in Bessel functions of the first and second kind and describing damped oscillations in the case of a stable unperturbed state and growing oscillations in the case of an unstable unperturbed state. The WKB theory of plane scalar-gravitational perturbations is constructed: dispersion equations are obtained in general form and solved for a neutral fluid. In this case, expressions are obtained for the local frequency and growth increment of oscillations, as well as the integral increment. It is shown that only free wave regimes or growing standing oscillations are possible during the evolution. Perturbations in the WKB approximation in a neutral fluid are studied and it is shown that local formulas for the evolution of perturbations correspond to the model of the 1985 article by M.Yu. The times of the beginning and end of the instability phase are determined and it is shown that instability can develop only at the unstable inflationary stage of the expansion of the Universe.

gr-qc↗
arXiv2024

Self-gravitating Higgs field of scalar charge

The self-gravitating Higgs field of a scalar charge has been studied. It is shown that in the zero and first approximation of the smallness of the scalar charge, the gravitational field of the scalar charge is described by the Schwarzschild-de Sitter metric with a cosmological constant determined by the vacuum potential of the Higgs field. An equation for the perturbation of the vacuum potential is obtained and studied. Particular exact solutions of the field equation are given. It is shown that in the case of a naked singularity, solutions to the field equation have the character of microscopic oscillations with a Compton wavelength. Limiting asymptotic cases of the behavior of solutions are studied and their comparative analysis is carried out in relation to the Fisher solution. The averaging of microscopic oscillations of the scalar field was carried out and it was shown that they make a negative contribution to the macroscopic energy of the scalar field, reducing the observed value of the Black Hole mass. A computer simulation of a scalar field has been carried out, demonstrating various types of behavior of solutions. Keywords: scalarly charged Black hole, scalar Higgs field, asymptotic behavior, macroscopic characteristics.

gr-qc↗
arXiv2023

Study of a complete model of the cosmological evolution of a classical scalar field with a Higgs potential. IV. Large-scale model transformations

A study and numerical modeling of the cosmological evolution of a classical scalar field with the Higgs potential was carried out. Based on the formulated similarity properties of cosmological models, their main characteristics are studied for models with different interaction scales: the Planck scale, the Grand Unified scale and the Standard Model scale. Based on numerical integration, the similarity properties of these models are proven with high accuracy.

gr-qc↗
arXiv2023

Formation of supermassive nuclei of Black holes in the early Universe by the mechanism of scalar-gravitational instability. III. Large scale picture

The dependence of the parameters of the evolution of scalarly charged Black Holes (BHs) in the early Universe on the parameters of field-theoretic theories of interaction, the influence of the geometric factor of the structure of the relative position of BHs on the limitation of their maximum mass are studied, the problem of the metric of a scalarly charged BH in a medium of expanding scalarly charged matter is discussed, the expression is obtained for the macroscopic cosmological constant at late stages of expansion, generated by quadratic fluctuations of the metric, connecting the value of the cosmological constant with the BH masses and their concentration. Keywords: scalarly charged plasma, cosmological model, Higgs scalar field, gravitational stability, spherical perturbations, black hole formation, effective cosmological constant.

gr-qc↗
arXiv2023

Formation of supermassive nuclei of Black holes in the early\\[8pt] Universe by the mechanism of scalar-gravitational instability. II. The evolution of localized spherical perturbations

Based on the previously formulated theory of spherical perturbations in the cosmological medium of self-gravitating scalarly charged fermions with the Higgs scalar interaction and the similarity properties of such models, the formation of supermassive Black Hole Seeds (SSBH) in the early Universe is studied. Using numerical simulation of the process, it is shown that the mass of SSBH during the evolution process reaches a limiting value, after which it begins to slowly fall. The possible influence of nonlinearity on this process is discussed.

gr-qc↗
arXiv2023

Formation of supermassive nuclei of Black holes in the early Universe by the mechanism of scalar-gravitational instability. I. Local picture

Based on the formulated and proven similarity properties of cosmological models based on a statistical system of degenerate scalarly charged fermions, as well as the previously identified mechanism of scalar-gravitational instability of cosmological models, a numerical-analytical study of the formation of supermassive black hole nuclei in the early Universe was carried out. A mathematical model of the evolution of spherical perturbations is constructed, on the basis of which the main regularities of the process of evolution of collapsing masses and the dependence of the parameters of forming black holes on the fundamental parameters of the cosmological model and the wavelength of gravitational perturbations are revealed. In this case, the mass loss of the black hole due to quantum evaporation is taken into account. A stable tendency for the early formation of supermassive black hole nuclei in the class of cosmological models under study is shown, and a close connection between the growth of masses of spherical perturbations and the nature of the singular points of these models is shown. Keywords: scalarly charged plasma, cosmological model, Higgs scalar field, gravitational stability, spherical perturbations, black hole formation, evaporation.

gr-qc↗
arXiv2023

Similarity of cosmological models and its application to the analysis of cosmological evolution

Scale transformations of cosmological models based on a statistical system of degenerate fermions with a scalar Higgs interaction are studied. The similarity properties of cosmological models are revealed under the scale transformation of their fundamental parameters. The laws of transformation of the coordinates of singular points and eigenvalues of the characteristic matrix of the dynamical system of the cosmological model under its scale transformations are established. With the help of the previously studied dynamical system of scalarly charged fermions is transformed to new variables and modified to a dynamical system with a nondegenerate characteristic matrix and its nondegenerate branch, the singular points and eigenvalues of the characteristic matrix are found, which coincide with the corresponding values for the vacuum field model. Examples of numerical simulation of such cosmological models are given. Keywords: scalarly charged plasma, cosmological model, Higgs scalar field, similarity trans\-for\-mation, qualitative analysis.

gr-qc↗
arXiv2023

Scalarly charged particles and interparticle interaction with the Higgs potential

Asymptotically exact solutions are obtained for a spherically symmetric field with the Higgs potential generated by a point scalar charge, and a method for numerical integration of the equation for a scalar field with the Higgs potential of a point charge is proposed. Examples of numerical modeling of the equation of the scalar field of a single charge are given. With the help of the solution obtained, solutions of the relativistic equations of motion of a scalar charge in an external scalar field of the Higgs type of a singular scalar source are found and some unique properties of the interparticle scalar interaction are revealed.

gr-qc↗
arXiv2023

Evolution of spherical perturbations in the cosmological environment of degenerate scalarly charged fermions with the Higgs scalar interaction

A mathematical model is constructed for the evolution of spherical perturbations in a cosmological one-component statistical system of completely degenerate scalarly charged fermions with a scalar Higgs interaction. A complete system of self-consistent equations for small perturbations describing the evolution of spherical perturbations is constructed. Singular parts in perturbation modes corresponding to point mass and scalar charge are singled out. Systems of ordinary differential equations are obtained that describe the evolution of the mass and charge of a singular source, and systems of partial differential equations that describe the evolution of non-singular parts of perturbations. In this case, the coefficients of partial differential equations are described by solutions of evolutionary equations for mass and charge. The problem of spatially localized perturbations for solutions polynomial in the radial coordinate is reduced to a recurrent system of ordinary linear differential equations for the coefficients of these polynomials. The properties of solutions in the case of cubic polynomials are studied, in particular, it is shown that the radii of localization of gravitational and scalar perturbations coincide and evolve in proportion to the scale factor. Numerical modeling of the evolution of perturbations was carried out, in particular, it confirmed the exponential growth of the central mass of the perturbation, and also revealed the oscillatory nature of the evolution of the scalar charge. Keywords: scalar charged plasma, cosmological model, scalar Higgs field, gravitational instability, spherical perturbations.

gr-qc↗
arXiv2023

Two-field model of gravitational-scalar instability and the formation of supermassive black holes in the early Universe

Based on the previously formulated mathematical model of a statistical system with scalar interaction of fermions and the theory of gravitational-scalar instability of a cosmological model based on a two-component statistical system of scalarly charged degenerate fermions, a numerical model of the cosmological evolution of gravitational-scalar perturbations in the presence of classical and phantom scalar fields is constructed and studied. The gravitational-scalar instability in the early stages of expansion in the model under study arises at sufficiently large scalar charges, and the instability develops near the unstable points of the vacuum doublet. Shortwave perturbations of the free phantom field turn out to be stable at stable singular points of the vacuum doublet. It is shown that for sufficiently large scalar charges, mass perturbations can grow to the values of masses Black Hole Seeds (BHS).

physics.gen-ph↗
arXiv2023

Gravitational-Scalar Instability of a Cosmological Model Based on a Two-Component System of Degenerate Scalarly Charged Fermions with Asymmetric Higgs Interaction. I. Equations for Perturbations

A mathematical model is formulated for the evolution of plane perturbations in a cosmological two-component statistical system of completely degenerate scalarly charged fermions with an asymmetric scalar Higgs interaction. A complete closed system of differential equations describing the unperturbed state of a homogeneous and isotropic system and a system of self-consistent evolution equations of small perturbations are constructed.

gr-qc↗
arXiv2023

Gravitational-Scalar Instability of a Cosmological Model Based on a Two-Component System of Degenerate Scalarly Charged Fermions with asymmetric Higgs Interaction. II. WKB-Aapproximation

Solutions of the system of evolutionary equations in the short-wavelength approximation are found and studied. A connection is established between the problem of the evolution of short-wavelength gravitational-scalar perturbations and the problem of eigenvectors and eigenvalues of a linear operator. By means of an applied mathematical package, a program for calculating the amplitudes of perturbations of the cosmological model was created. It is shown that unstable short-wavelength perturbation modes arise in such a system. A numerical model for the evolution of gravitational-scalar perturbations of the cosmological model has been constructed and analyzed.

physics.gen-ph↗
arXiv2022

Single-Field Model of Gravitational-Scalar Instability. II. Black Hole Formation

On the basis of the previously formulated mathematical model of a statistical system with scalar interaction of fermions and the theory of gravitational-scalar instability of a cosmological model based on a one-component statistical system of scalarly charged degenerate fermions (\MIO models), the possibility of the formation of black holes in the early Universe using the mechanism of gravitational-scalar instability, which ensures the exponential growth of perturbations. The evolution of spherical masses in the \MIO model, as well as the evolution of black holes with allowance for their evaporation, is studied. The argumentation of the possibility of the formation of black holes in the early Universe with the help of the proposed mechanism is given, and a numerical model is constructed that confirms this argumentation. The range of parameters of the \MIO model, which ensures the growth of black hole masses in the early Universe up to $10^4\div10^6 M_\odot$, is identified.

gr-qc↗
arXiv2022

Single-field model of gravitational-scalar instability. I. Evolution of perturbations

On the basis of the previously formulated mathematical model of a statistical system with a scalar interaction of fermions and the theory of gravitational-scalar instability of a cosmological model based on a two-component statistical system of scalarly charged degenerate fermions, a numerical model of the cosmological evolution of gravitational-scalar perturbations for a one-component cosmological system with a canonical scalar interaction is constructed and studied. The influence of the magnitude of the scalar charge of fermions on the differential and integral parameters of the instability is revealed. It is shown that the gravitational-scalar instability in the early stages of expansion in the model under study arises at sufficiently small scalar charges. 4 fundamentally different types of perturbations are identified, as well as 4 types of gravitational-scalar instability, determined by the fundamental parameters of the model. Examples of numerical models are given that provide large values of the increments of the increase in the amplitude of perturbations.

gr-qc↗