arXiv subjects

Vladimir Dzhunushaliev

Publications and source records attributed to Vladimir Dzhunushaliev.

At least 37 records · Page 2Linked to original sources

arXiv2023

Spinor domain wall and test fermions on an arbitrary domain wall

We consider a spinor domain wall embedded in a five-dimensional spacetime with a nondiagonal metric. The corresponding plane symmetric solutions for linear and nonlinear spinor fields with different parameters are obtained. It is shown that in the general case the metric functions and spinor fields do not possess $Z_2$ symmetry with respect to the domain wall. We study the angular momentum density of the domain wall arising because of the presence of the spinor field creating the wall. The properties of test fermions located on an arbitrary domain wall are considered. The concepts of the ``second spin'' (arising due to the properties of the Lorentz group generators in a five-dimensional spacetime) and of the ``second magnetic field'' (representing the components $F_{i 5}$ of the electromagnetic field five-tensor) are introduced. We find eigenspinors of the ``second spin'' and show that some of them represent the Bell states. In the nonrelativistic limit we derive the Pauli equation for the test fermions on the domain wall which contains an extra term describing the interaction of a spin-$1/2$ particle with the ``second magnetic field''; this allows the possibility of an experimental verification of the existence of extra dimensions.

gr-qc↗

arXiv2023

Charge gap in SU(3) Yang-Mills-plus-nonlinear-spinor-field theory

Particlelike solutions in SU(3) gauge Yang-Mills theory with color magnetic and electric fields sourced by a nonlinear spinor field are obtained. The asymptotic behavior of these fields is studied. It is shown that the electric field exhibits the Coulomb asymptotic behavior, and one of the color components of the magnetic field behaves asymptotically as the field of a magnetic dipole. This allows one to determine the corresponding charge and magnetic moment. It is shown that profiles of the color charge and magnetic moment have global minima, which may be called charge and magnetic moment gaps. The relationship between the total energy of the system and the color charge is obtained. The physical reason for the appearance of the mass, charge, and magnetic moment gaps in the theory under consideration is discussed.

hep-th↗

arXiv2023

Mixed neutron-star-plus-wormhole systems: Rotating configurations

We present rapidly rotating neutron stars featuring wormholes in their centers. They arise in general relativity in the presence of a ghost scalar field. The nuclear matter is described by a polytropic equation of state, yielding realistic masses and radii for the neutron stars. The wormholes possess small circumferential radii of size up to 3 km. With increasing wormhole size, the masses and radii of the stars decrease, while the domain of existence of these rotating mixed neutron-star-plus-wormhole systems retains the characteristic properties of a rotating neutron star domain. The question of stability of the mixed configurations under consideration is briefly discussed.

gr-qc↗

arXiv2022

QCD effects in non-QCD theories

It is shown that, in some non-QCD theories, there are effects shared by QCD: (i)~in SU(2) Yang-Mills theory containing a nonlinear spinor field, there is a mass gap; (ii)~in SU(3) Proca-Higgs theory, there are flux tube solutions with a longitudinal electric field required for producing a force binding quarks; (iii)~in non-Abelian Proca-Higgs theories, there exist flux tube solutions with a momentum directed along the tube axis and particlelike solutions with a nonvanishing total angular momentum created by crossed color electric and magnetic fields; in QCD, such configurations may contribute to the proton spin. We discuss the conjecture that such non-QCD theories might be a consequence of approximate solution of an infinite set of Dyson-Schwinger equations describing the procedure of nonperturbative quantization. The phenomenon of dimensional transmutation for nonperturbative quantization and the analogy between nonperturbative quantization and turbulence modeling are also discussed.

hep-ph↗

arXiv2022

Quantization of measure in gravitation

Using the Radon-Nikodym theorem concerning the relation between any two measures, as well as the methods employed in loop quantum gravity, it is shown that, in gravitation, one can quantize any measure which is not even associated with metric. We have considered the simplest case where the proportionality coefficient between two operators of measure (the Radon-Nikodym derivative) is some function. The result is that in the right-hand side of the commutation relations for the measure the fundamental length becomes a variable quantity, and this can lead to smoothing the singularity. The case where the Radon-Nikodym derivative is an operator is also under discussion. Classical and quantum theories on the background of space endowed with quantum measure are under consideration.

gr-qc↗

arXiv2022

Rapidly rotating Dirac stars

Within general relativity, we construct sequences of rapidly rotating Dirac stars consisting of a spinor fluid described by an effective equation of state. We find the physically relevant domain of stable configurations and calculate their principal characteristics which are completely determined by the central density of the spinor fluid, the mass of the nonlinear spinor field, and the velocity of rotation. It is demonstrated that for a certain choice of the spinor field mass, the main physical characteristics of the Dirac stars are close to those that are typical of rotating neutron stars.

gr-qc↗

arXiv2022

Quasiparticles in nonperturbative vacuum

The model of nonperturbative vacuum in SU(2) Yang-Mills theory coupled to a nonlinear spinor field is suggested. By analogy with Abelian magnetic monopole dominance in quantum chromodynamics, it is assumed that the dominant contribution to such vacuum is coming from quasiparticles described by dipolelike solutions existing in this theory. Using an assumption of the behavior of the number density of quasiparticles whose energy approaches infinity, we derive an approximate expression for the energy density of such nonperturbative vacuum, which turns out to be finite, unlike an infinite energy density of perturbative vacuum. Using characteristic values of the parameters appearing in the expression for the nonperturbative energy density, it is shown that this density may be of the order of the energy density associated with Einstein's cosmological constant. The physical interpretation of the spinor field self-coupling constant as a characteristic distance between quasiparticles is suggested. The questions of experimental verification of the nonperturbative vacuum model under consideration and of determining its pressure are briefly discussed.

hep-th↗

arXiv2022

Proca balls with angular momentum or flux of electric field

Within SU(2) Higgs-Proca theory, we obtain a family of nontopological static solutions describing localized, finite-energy configurations (Proca balls). The gauge symmetry of the theory is explicitly broken by introducing a vector Proca field whose components have different masses. Such solutions describe particlelike systems,the crucial feature of which is that they either possess a nonzero total angular momentum or have a flux of electric field through the plane of symmetry of such objects. It is shown that the angular momentum is provided by static crossed electric and magnetic fields. The existence of the solutions is caused by the fact that we circumvent the conditions of the no-go theorem, according to which there are no stationary and axially symmetric spinning excitations for the 't~Hooft-Polyakov monopoles, Julia-Zee dyons, sphalerons, and also vortices. The dependence of some integral physical quantities on the ratio of the Proca-field masses is studied. It is demonstrated that the inclusion of external sources (charges) enables one to obtain solutions with equal Proca-field masses. We also discuss the possibilities of using quarks as sources of the Proca field under investigation and for treating the Proca balls as glueballs in SU(2) Higgs-Proca theory.

hep-th↗

arXiv2022

Mass gap for a monopole interacting with different nonlinear spinor fields

We study the properties of the mass gap for monopole solutions in SU(2) Yang-Mills theory with a source of the non-Abelian gauge field in the form of a spinor field described by the nonlinear Dirac equation. Different types of nonlinearities parameterized by the parameter $λ$ are under consideration. It is shown that for the range of values of this parameter studied in the present paper the value of the mass gap depends monotonically on this parameter, and the position of the mass gap does not practically depend on $λ$.

hep-th↗

arXiv2021

Axially symmetric Proca-Higgs boson stars

We consider strongly gravitating configurations consisting of coupled real Higgs scalar field and vector (Proca) field of mass $μ_P$. For such a system, we find static regular axially symmetric solutions describing asymptotically flat configurations which may be referred to as Proca-Higgs miniboson stars, since their total mass and spatial dimension are of order $M_{\text{Pl}}^2/μ_P$ and $μ_P^{-1}$, respectively.The system possesses an axially symmetric dipole field and may be regarded as a Proca dipole.

gr-qc↗

arXiv2021

Axially symmetric particlelike solutions with the flux of a magnetic field in the non-Abelian Proca-Higgs theory

Within the non-Abelian SU(2) Proca-Higgs theory, we study localised axially symmetric solutions possessing a finite field energy. It is shown that in a certain sense such solutions are analogues of the Nielsen-Olesen tube, since they have a longitudinal magnetic field creating a flux of this field over the central cross-section of the Proca tube. The main difference between the Proca tube and the Nielsen-Olesen tube is that the Proca tube is described by a topologically trivial solution and has finite size, since its energy density decreases exponentially with distance. The dependence of the total field mass of the Proca tube on the value of one of the parameters determining the solution is examined in detail. The solutions are obtained both in the presence and in the absence of external sources (charge and current densities).

hep-ph↗

arXiv2021

Static and collapsing configurations supported by the spinor fluid

We study a gravitating spherically symmetric nonrelativistic configuration consisting of a spinor fluid whose effective equation of state is derived from a consideration of a limiting system supported by a massive nonlinear spinor field. For such a configuration, we find a two-parametric family of static regular solutions describing compact objects whose masses and sizes are determined by the central density of the spinor fluid and the mass of the spinor field. Using the similarity method, we consider a gravitational collapse of an initially uniform system consisting of the spinor fluid. We estimate the general characteristics of the collapse and show that a resulting nonuniform distribution of the fluid occurs that may serve as a core for the creation of equilibrium starlike configurations.

gr-qc↗

arXiv2021

Masking singularities in Weyl gravity and Ricci flows

Within vacuum Weyl gravity, we obtain a solution by which, using different choices of the conformal factor, we derive metrics describing (i)~a bounce of the universe; (ii)~toroidal and spherical wormholes; and (iii)~a change in metric signature. It is demonstrated that singularities occurring in these systems are "masked". We give a simple explanation of the possibility of masking the singularities within Weyl gravity. It is shown that in the first and third cases the three-dimensional metrics form Ricci flows. The question of the possible applicability of conformal Weyl gravity as some phenomenological theory in an approximate description of quantum gravity is discussed.

gr-qc↗

arXiv2021

Model of a spin-$1/2$ electric charge in $F\left( B^2\right)$ modified Weyl gravity

Within $F\left( B^2\right)$ modified Weyl gravity, we consider a model of a spin-$1/2$ electric charge consisting of interior and exterior regions. The interior region is determined by quantum gravitational effects whose approximate description is carried out using Weyl gravity nonminimally coupled to a massless Dirac spinor field. The interior region is embedded in exterior Minkowski spacetime, and the joining surface is a two-dimensional torus. It is shown that mass, electric charge, and spin of the object suggested may be the same as those for a real electron.

gr-qc↗

arXiv2021

Linear energy density and the flux of an electric field in Proca tubes

We study cylindrically symmetric solutions within SU(3) non-Abelian Proca theory coupled to a Higgs scalar field. The solutions describe tubes containing either the flux of a color electric field or the energy flux and momentum. It is shown that the existence of such tubes depends crucially on the presence of the Higgs field (there are no such solutions without this field). We examine the dependence of the integral characteristics (linear energy and momentum densities) on the values of the electromagnetic potentials at the center of the tube, as well as on the values of the coupling constant of the Higgs scalar field. The solutions obtained are topologically trivial and they demonstrate the dual Meissner effect: the electric field is pushed out by the Higgs scalar field.

hep-ph↗

arXiv2021

Nonperturbative quantization approach for QED on the Hopf bundle

We consider the Dirac equation and Maxwell's electrodynamics in $\mathbb{R} \times S^3$ spacetime, where a three-dimensional sphere is the Hopf bundle $S^3 \rightarrow S^2$. In both cases, discrete spectra of classical solutions are obtained. Based on the solutions obtained, the quantization of free, noninteracting Dirac and Maxwell fields is carried out. The method of nonperturbative quantization of interacting Dirac and Maxwell fields is suggested. The corresponding operator equations and the infinite set of the Schwinger-Dyson equations for Green's functions is written down. To illustrate the suggested scheme of nonperturbative quantization, we write a simplified set of equations describing some physical situation. Also, we discuss the properties of quantum states and operators of interacting fields.

hep-th↗

arXiv2020

Proca tubes with the flux of the longitudinal chromoelectric field and the energy flux/momentum density

We consider non-Abelian SU(3) Proca theory with a Higgs scalar field included. Cylindrically symmetric solutions describing classical tubes either with the flux of a longitudinal electric field or with the energy flux (and hence with nonzero momentum density) are obtained. It is shown that, in quantum Proca theory, there can exist tubes both with the flux of the longitudinal electric field and with the energy flux/momentum density simultaneously. An imaginary particle -- Proca proton~-- in which `quarks' are connected by tubes with nonzero momentum density is considered. It is shown that this results in the appearance of the angular momentum related to the presence of the non-Abelian electric and magnetic fields in the tube, and this angular momentum is a part of the Proca proton spin.

hep-ph↗

arXiv2020

On the linear stability of polytropic fluid spheres in $R^2$ gravity

Within $R^2$ gravity, we study the linear stability of strongly gravitating spherically symmetric configurations supported by a polytropic fluid. All calculations are carried out in the Jordan frame. It is demonstrated that, as in general relativity, the transition from stable to unstable systems occurs at the maximum of the curve mass-central density of the fluid.

gr-qc↗