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N. G. Tokarevskaya

Publications and source records attributed to N. G. Tokarevskaya.

16 recordsLinked to original sources

Graviton in a Curved Space-Time Background and Gauge Symmetry

Pauli-Fierz approach to description of a massless spin-2 particle is investigated in the framework of 30-component first order relativistic wave equation theory on a curved space-time background. It is shown that additional gauge symmetry of massless equations established by Pauli-Fierz can be extended only to curved space-time regions where Ricci tensor vanishes. In all such space-time models the generally covariant S=2 massless wave equation exhibits gauge symmetry property, otherwise it is not so.

math-ph↗

Exact solutions for a quantum-mechanical particle with spin 1 and additional intrinsic characteristics in a homogeneous magnetic field

With the use of the general covariant matrix 10-dimensional Petiau-Duffin-Kemmer formalism in cylindrical coordinates exact solutions of the quantum-mechanical equation for a particle with spin 1 in the presence of an external homogeneous magnetic field are constructed. Three linearly independent types of solutions are separated; in each case the formula for the energy levels has been found.Within similar technique for the quantum-mechanical equation for a particle with spin 1 and additional intrinsic electromagnetic characteristics - polarizability, exact solutions are found in the presence of an external homogeneous magnetic field.

quant-ph↗

Shapiro's plane waves in spaces of constant curvature and separation of variables in real and complex coordinates

The aim of the article to clarify the status of Shapiro plane wave solutions of the Schrödinger's equation in the frames of the well-known general method of separation of variables. To solve this task, we use the well-known cylindrical coordinates in Riemann and Lobachevsky spaces, naturally related with Euler angle-parameters. Conclusion may be drawn: the general method of separation of variables embraces the all plane wave solutions; the plane waves in Lobachevsky and Riemann space consist of a small part of the whole set of basis wave functions of Schrödinger equation. In space of constant positive curvature $S_{3}$, a complex analog of horospherical coordinates of Lobachevsky space $H_{3}$ is introduced. To parameterize real space $S_{3}$, two complex coordinates $(r,z)$ must obey additional restriction in the form of the equation $r^{2} = e^{z-z^{*}} - e^{2z} $. The metrical tensor of space $S_{3}$ is expressed in terms of $(r,z)$ with additional constraint, or through pairs of conjugate variables $(r,r^{*})$ or $(z,z^{*})$; correspondingly exist three different representations for Schrödinger Hamiltonian. Shapiro plane waves are determined and explored as solutions of Schrödinger equation in complex horosperical coordinates of $S_{3}$. In particular, two oppositely directed plane waves may be presented as exponentials in conjugated coordinates. $Ψ_{-}= e^{-αz}$ and $Ψ_{+}= e^{-αz^{*}}$. Solutions constructed are single-valued, finite, and continuous functions in spherical space and correspond to discrete energy levels.

math-ph↗

Maxwell equations in matrix form, squaring procedure, separating the variables, and structure of electromagnetic solutions

The Riemann -- Silberstein -- Majorana -- Oppenheimer approach to the Maxwell electrodynamics in vacuum is investigated within the matrix formalism. The matrix form of electrodynamics includes three real 4 \times 4 matrices. Within the squaring procedure we construct four formal solutions of the Maxwell equations on the base of scalar Klein -- Fock -- Gordon solutions. The problem of separating physical electromagnetic waves in the linear space λ_{0}Ψ^{0}+λ_{1}Ψ^{1}+λ_{2}Ψ^{2}+ lambda_{3}Ψ^{3} is investigated, several particular cases, plane waves and cylindrical waves, are considered in detail.

math-ph↗

Maxwell Equations in Complex Form, Spherical Waves in Spaces of Constant Curvature of Lobachevsky and Riemann

Complex formalism of Riemann - Silberstein - Majorana - Oppenheimer in Maxwell electrodynamics is extended to the case of arbitrary pseudo-Riemannian space - time in accordance with the tetrad recipe of Tetrode - Weyl - Fock - Ivanenko. In this approach, the Maxwell equations are solved exactly on the background of simplest static cosmological models, spaces of constant curvature of Riemann and Lobachevsky parameterized by spherical coordinates. Separation of variables is realized in the basis of Schrödinger -- Pauli type, description of angular dependence in electromagnetic complex 3-vectors is given in terms of Wigner D-functions. In the case of compact Riemann model a discrete frequency spectrum for electromagnetic modes depending on the curvature radius of space and three discrete parameters is found. In the case of hyperbolic Lobachevsky model no discrete spectrum for frequencies of electromagnetic modes arises.

math-ph↗

Factorizations for 3-rotations and polarization of the light in Mueller-Stokes an Jones formalisms

Formulas describing all 2-element and 3-element factorizations of arbitrary element of the groups SU(2) and SO(3,R) are derived. Six 2-element factorizations, $ (U_{2}U_{3}U'_{2}), (U_{3}U_{2}U'_{3}), (U_{3}U_{1}U'_{3}), (U_{1}U_{3}U'_{1}), (U_{1}U_{2}U'_{1}), (U_{2}U_{1}U'_{2})$, provide all possible way to define Euler type angles; and six 3-element ones, $ (U_{1}U_{2}U_{3}), (U_{1}U_{3}U'_{2}), (U_{2}U_{3}U_{1}), (U_{2}U_{1}U_{3}), (U_{3}U_{1}U_{2}), (U_{3}U_{2}U_{1})$ provide all possible ways to parameterize the unitary and orthogonal groups by three elementary angles. In thecontext the light polarization formalism of Stokes-Mueller vectors and Jones spinors, relations produced give a base to resolve arbitrary pure polarization rotators into all possible sets of elementary rotators of two or three constituents.

math-ph↗

Matrix-based approach to electrodynamics in media

The Riemann -- Silberstein -- Majorana -- Oppenheimer approach to the Maxwell electrodynamics in presence of electrical sources and arbitrary media is investigated within the matrix formalism. The symmetry of the matrix Maxwell equation under transformations of the complex rotation group SO(3.C) is demonstrated explicitly. In vacuum case, the matrix form includes four real $4 \times 4$ matrices $α^{b}$. In presence of media matrix form requires two sets of $4 \times 4$ matrices, $α^{b}$ and $β^{b}$ -- simple and symmetrical realization of which is given. Relation of $α^{b}$ and $β^{b}$ to the Dirac matrices in spinor basis is found. Minkowski constitutive relations in case of any linear media are given in a short algebraic form based on the use of complex 3-vector fields and complex orthogonal rotations from SO(3.C) group. The matrix complex formulation in the Esposito's form,based on the use of two electromagnetic 4-vectors, $e^α(x) = u_β F^{αβ}(x), b^α (x) = u_β \tilde{F}^{αβ}(x) $ is studied and discussed. It is argued that Esposito form is achieved trough the use of a trivial identity $I=U^{-1}(u)U(u)$ in the Maxwell equation.

math-ph↗

4 x 4 matrices in Dirac parametrization: inversion problem and determinant

Parametrization of complex 4 x 4 - matrices G in terms of Dirac tensor parameters (A,B,A_{l},B_{l},F_{kl}) or equivalent four complex 4-vectors (k,m,n,l) is investigated. In the given parametrization, the problem of inverting any 4 x 4 matrix G is solved. Expression for determinant of any matrix G is found: det G = F(k,m,n,l).

hep-th↗

Duffin-Kemmer-Petiau formalism reexamined: non-relativistic approximation for spin 0 and spin 1 particles in a Riemannian space-time

It is shown that the generally covariant Duffin-Kemmer-Petiau equation, formulated in the frame of the Tetrode-Weyl-Fock-Ivanenko tetrad formalism, allows for a non-relativistic approximation if the metric tensor is of a special form. The Pauli equation for a vector particle involves the Riemann curvature tensor explicitly. In analogous way, the procedure of the non-relativistic approximation in the theory of scalar particle, charged and neutral, is investigated in the background of Riemannian space-time. A generalized covariant Schrodinger equation is derived when taking into account non-minimal interaction term through scalar curvature R(x), it substantially differs from the conventional generally covariant Schrodinger equation produced when R(x)=0. It is demonstrated that the the non-relativistic wave function is always complex-valued irrespective of the type of relativistic scalar particle, charged or neutral, taken initially. The theory of vector particle proves the same property: even if the wave function of the relativistic particle of spin 1 is taken real,the corresponding wave function in the non-relativistic approximation is complex-valued.

hep-th↗

Maxwell equations in Riemannian space-time, geometry effect on material equations in media

The known possibility to consider the (vacuum) Maxwell equations in a curved space-time as Maxwell equations in flat space-time(Mandel'stam L.I., Tamm I.E.) taken in an effective media the properties of which are determined by metrical structure of the curved model is studied. Metrical structure of the curved space-time generates effective constitutive equations for electromagnetic fields, the form of four corresponding symmetrical tensors is found explicitly for general case of an arbitrary Riemannian space - time. Four constitutive tensors are not independent and obey some additional constraints between them. Several simple examples are specified in detail:itis given geometrical modeling of the anisotropic media (magnetic crystals) and the geometrical modeling of a uniform media in moving reference frame in the Minkowsky electrodynamics -- the latter is realized trough the use of a non-diagonal metrical tensor determined by 4-vector velocity of the moving uniform media. Also the effective material equations generated by geometry of space of constant curvature (Lobachevsky and Riemann models) are determined.

physics.class-ph↗

On 15-component theory of a charged spin-1 particle with polarizability in Coulomb and Dirac monopole fields

The problem of a spin 1 charged particle with electromagnetic polarizability, obeying a generalized 15-component quantum mechanical equation, is investigated in presence of the external Coulomb potential. With the use of the Wigner's functions techniques, separation of variables in the spherical tetrad basis is done and the 15-component radial system is given. It is shown that there exists a class of quantum states for which the additional characteristics, polarizability, does not manifest itself anyhow; at this the energy spectrum of the system coincides with the known spectrum of the scalar particle. For j=0 states, a 2-order differential equation is derived, it contains an additional potential term 1/r^{4}. In analogous approach wave functions the generalized particle are examined in presence of external Dirac monopole field. It is shown that there exists one special state with minimal conserved quantum number j_{min}. It this solution, first, the polarizability does not exhibits itself. Analysis of the usual vector particle in external Coulomb potential is given. It is shown that at j=0 some bound states will arise. The corresponding energy spectrum is found.

hep-th↗

On the theory of a scalar particle with electromagnetic polarizability in Coulomb and Dirac monopole fields

15-component matrix and tetrad-based description of a a scalar particle with two electromagnetic characteristics -- charge e and polarizability σ, is elaborated in presence of external Coulomb field. With the use of Wigner's D-functions, in the basis of diagonal spherical tetrad, the separation of variables in the generalized wave equation is done, and a system of 15 radial equations is given. It is shown that the radial system is reduced to a generalized Klein-Fock radial equation with an additional term of the form r^{-4}. In the framework of the analogous approach a scalar particle with charge e and polarizability σis investigated in presence of the field of a magnetic charge g. The separation of variables is done. Again all the radial system is reduced to a single differential equation of second order with an additional term of the form r^{-4} . This means that because of the known peculiar properties of the potential r^{-4} (an absorbing center), the monopole influence on the scalar particle with σ-characteristics is much more noticeable in the radial equation than in the case of usual particle.

hep-th↗

On conserved quantities in the theory of charged boson fields of spin 0 and 1

Bosons of spin 0 and 1, with different intrinsic parities, are described by full sets of spinor equations in the frame of the Dirac-Kahler theory. This enables us to obtain the conservation laws for the boson particles with one value of spin by imposing linear additional conditions in the known sixteen conserved currents of the Dirac-Kahler field. In this way for each boson the known conserved quantities, charge vector j^{a}(x), symmetrical energy-momentum tensor T^{ab(x), and angular moment tensor L^{a[bc]}(x), have been found. Additionally, for scalar fields, one conserved current ν^{a}(x) has been constructed; it is not zero one only for a complex-valued field. For a vector particles, two additional currents, ν^{a}(x) and ν^{ab}(x), are found that again do not vanish when fields are complex-valued. Those currents ν^{a}(x) and ν^{ab}(x) have not seemingly any physical interpretation.

hep-th↗

Petras Theory of a Spin-1/2 Particle in Electromagnetic and Gravitational Fields

20-component Petras theory of 1/2-spin particle with anomalous magnetic momentum in presence of external electromagnetic and gravitational fields is investigated. The gravitation field is described as space-time curvature. Correctness of the constructed equations in the sense of general relativity and gauge local Lorentz symmetry is proved in detail. Tetrad P-symmetry of the equations is demonstrated. A generally covariant representation of the invariant bilinear form matrix is established and the conserved current of the 20-componen t field is constructed. It is shown that after exclusion of the additional vector-bispinor Ψ_β(x) the wave equation for the principal Ψ-bispinor looks as generally covariant Dirac's equation with electromagnetic minimal and Pauli interactions and with an additional gravitational interaction through scalar curvarture R(x)-term. The massless case is analyzed in detail. The conformal non-invariance of the massless equation is demonstrated and new conformally invariant equations for 20-component field are proposed.

hep-th↗

Spin 1 Particle in a 15-Component Formalism, Interaction with Electromagnetic and Gravitational Fields

A generalized vector particle theory with the use of an extended set of Lorentz group irredicible representations, including scalar, two 4-vectors, and antisymmetric 2-rang tensor, is investigated. Initial equations depend upon four complex parameters $λ_{i}$, obeying two supplementary conditions, so restriction of the model to the case of electrically neutral vector particle is not a trivial task. A special basis in the space of 15-component wave functions is found where instead of four $λ_{i}$ only one real-valued quantity $σ$, a bilinear combination of $λ_{i}$, is presented. This $λ$-parameter is interpreted as an additional electromagnetic characteristic of a charged vector particle, polarizability. It is shown that in this basis $C$-operation is reduced to the complex conjugation only, without any accompanying linear transformation. Restriction to a massless vector particle is determined. Extension of the whole theory to the case of Riemannian space-time is accomplished. Two methods of obtaining corresponding generally covariant wave equations are elaborated: of tensor- and of tetrad-based ones. Their equivalence is proved. It is shown that in case of pure curved space-time models without Cartan torsion no specific additional interaction terms because of non-flat geometry arise. The conformal symmetry of a massless generally covariant equation is demonstrated explicitly. A canonical tensor of energy-momentum $T_{βα}$ is constructed, its conservation law happens to involves the Riemann curvature tensor. Within the framework of known ambiguity of any energy-momentum tensor, a new tensor $\bar{T}_{βα}$ is suggested to be used, which obeys a common conservation law.

hep-th↗

On Equations for a Spin-2 Particle in External Gravitational Field

30-component, of the first order, equation for a spin 2 particle, equivalent to the second order Pauli-Fierz one, is generalized to presence of an external electromagnetic field as well as a curved background space-time geometry. The essential property of the generally covariant wave equation obtained is that here from the very beginning, in accordance with requirement of the Pauli-Fierz approach, a set of additional relations on 30-component wave function for eliminating complementary spin 0 and spin 1 fields is present at the starting equation.

hep-th↗