91 research outputs found
Generally relativistical Tetrode-Weyl-Fock-Ivanenko formalism and behaviour of quantum-mechanical particles of spin 1/2 in the Abelian monopole field
Some attention in the literature has been given to the case of a particle of
spin 1/2 on the background of the external monopole potential. Some aspects of
this problem are reexamined here. The primary technical novelty is that the
tetrad generally relativistic method of Tetrode-Weyl-Fock-Ivanenko for
describing a spinor particle is exploited. The choice of the formalism has
turned out to be of great fruitfulness for examining the system. It is matter
that, as known, the use of a special spherical tetrad in the theory of a spin
1/2 particle had led Schrodinger to a basis of remarkable features. The basis
has been used with great efficiency by Pauli in his investigation on the pro-
blem of allowed spherically symmetric wave functions in quantum mechanics. For
our purposes, just several simple rules extracted from the much more com-
prehensive Pauli's analysis will be quite sufficient; those are almost mnemo-
nic working regulations. So, one may remember some very primary facts of D-
functions theory and then produce automatically proper wave functions. It seems
rather likely, that there may exist a generalized analog of such a re-
presentation for J(i)-operators, that might be successfully used whenever in a
linear problem there exists a spherical symmetry, irrespective of the con-
crete embodiment of such a symmetry. In particular, the case of electron in the
external Abelian monopole field completely come under the Sch-Pau method.Comment: 27 pages, Latex20
Generally relativistical Daffin-Kemmer formalis and behaviour of quantm-mechanical particle of spin 1 in the Abelian monopole field
It is shown that the manner of introducing theinteraction between a spin 1
particle and external classical gravitational field can be successfully uni-
fied with the approach that occurred with regard to a spin 1/2 particle and was
first developed by Tetrode, Weyl, Fock, Ivanenko. On that way a general- ly
relativistical Duffin-Kemmer equation is costructed. So, the manner of
extending the flat space Dirac equation to general relativity case indicates
clearly that the Lorentz group underlies equally both these theories. In other
words, the Lorentz group retains its importance and significance at changing
the Minkowski space model to an arbitrary curved space-time. In contrast to
this, at generalizing the Proca formulation, we automatically destroy any
relations to the Lorentz group, although the definition itself for a spin 1
particle as an elementary object was based on just this group. Such a gravity's
sensitiveness to the fermion-boson division might appear rather strange and
unattractive asymmetry, being subjected to the criticism. Moreover, just this
feature has brought about a plenty of speculation on this matter. In any case,
this peculiarity of particle-gravity field inter- action is recorded almost in
every handbook. In the paper, on the base of the Duffin-Kemmer formalism
developed, the problem of a vector particle in the Abelian monopole potential
is considered.Comment: 17 pages, Latex20
The doublet of Dirac fermions in the field of the non-Abelia monopole and parity selection rules
The paper concerns a problem of Dirac fermion doublet in the external
monopole potential arisen out of embedding the Abelian monopole solution in the
non-Abe- lian scheme. In this particular case, the Hamiltonian is invariant
under some symmetry operations consisting of an Abelian subgroup in the complex
rotational group SO(3.C). This symmetry results in a certain (A)-freedom in
choosing a discrete operator entering the complete set {H, j^{2}, j_{3}, N(A),
K} . The same complex number A represents a parameter of the wave functions
constructed. The generalized inversion-like operator N(A) implies its own
(A-dependent) de- finition for scalar and pseudoscalar, and further affords
some generalized N(A)-parity selection rules. It is shown that all different
sets of basis func- tions Psi(A) determine the same Hilbert space. In
particular, the functions Psi(A) decompose into linear combinations of
Psi(A=0). However, the bases con- sidered turn out to be nonorthogonal ones
when A is not real number; the latter correlates with the non-self-conjugacy
property of the operator N(A) at those A-s.
(This is a shortened version of the paper).Comment: 15 pages, latex20
On solutions of Schrodinger and Dirac equations in spaces of constant curvature, spherical and elliptical models
Exact solutions of the Schrodinger and Dirac equations in generalized
cylindrical coordinates of the 3-dimensional space of positive constant
curvature, spherical model, have been obtained. It is shown that all basis
Schrodinger's and Dirac's wave functions are finite, single-valued, and
continuous everywhere in spherical space model S_{3}. The used coordinates
(\rho, \phi,z) are simply referred to Eiler's angle variables (\alpha, \beta,
\gamma), parameters on the unitary group SU(2), which permits to express the
constructed wave solutions \Psi(\rho, phi,z) in terms of Wigner's functions
. Specification of the analysis to the case
of elliptic, SO(3.R) group space, model has been done. In so doing, the results
substantially depend upon the spin of the particle. In scalar case, the part of
the Schrodinger wave solutions must be excluded by continuity considerations,
remaining functions are continuous everywhere in the elliptical 3-space. The
latter is in agrement with the known statement: the Wigner functions
D_{mm'}^{j}(\alpha, \beta, \gamma) at j =0,1,2,... make up a correct basis in
SO(3.R) group space. For the fermion case, it is shown that no Dirac solutions,
continuous everywhere in elliptical space, do exist. Description of the Dirac
particle in elliptical space of positive constant curvature cannot be correctly
in the sense of continuity adjusted with its topological structure.Comment: 54 pages. Report to 13th International School & Conference
"Foundation & Advances in Nonlinear Science", Eds.: Kuvshinov V.I., Krylov
G.G., Minsk, 200
On WKB-Quantization for Kepler Problem in Euclide, Riemann and Lobachevsky 3-Space
Quantum mechanical WKB-method is elaborated for the known quantum Kepler
problem in curved 3-space models Euclide, Riemann and Lobachevsky in the
framework of the complex variable function theory. Generalized Schr\"{o}dinger,
Klein-Fock hydrogen atoms are considered. Exact energy levels are found and
their exactness is proved on the base of exploration into -degree terms of
the WKB-series. Dirac equation is solved too, but only approximate energy
spectrum is established.Comment: 18 page
Particle with spin S=3/2 in Riemannian space-time
Equations for 16-component vector-bispinor field, originated from
Rarita-Schwinger Lagrangian for spin 3/2 field extended to Riemannian
space-time are investigated. Additional general covariant constrains for the
field are produced, which for some space-time models greatly simplify original
wave equation.
Peculiarities in description of the massless spin 3/2 field are specified. In
the flat Minkowski space for massless case there exist gauge invariance of the
main wave equation, which reduces to possibility to produce a whole class of
trivial solutions in the the form of 4-gradient of arbitrary (gauge) bispinor
function, \Psi ^{0}_{c} = \partial_{c} \psi. Generalization of that property
for Riemannian model is performed; it is shown that in general covariant case
solutions of the gradient type \Psi^{0}_{\beta} = (\nabla_{\beta} +
\Gamma_{\beta})\Psi exist in space-time regions where the Ricci tensor obeys an
identity R_{\alpha \beta} - {1 \over 2} R g_{\alpha \beta} = 0.Comment: 12 pages, 61 references, Chapter 7 in: V.M. Red'kov, Fields in
Riemannian space and the Lorentz group (in Russian). Publishing House
"Belarusian Science", Minsk, 200
Monopole BPS-Solutions of the Yang-Mills Equations in Space of Euclid, Riemann, and Lobachevski
Procedure of finding of the Bogomolny-Prasad-Sommerfield monopole solutions
in the Georgi-Glashow model is investigated in detail on the backgrounds of
three space models of constant curvature: Euclid, Riemann, Lobachevski's.
Classification of possible solutions is given. It is shown that among all
solutions there exist just three ones which reasonably and in a one-to-one
correspondence can be associated with respective geometries. It is pointed out
that the known non-singular BPS-solution in the flat Minkowski space can be
understood as a result of somewhat artificial combining the Minkowski space
background with a possibility naturally linked up with the Lobachewski
geometry. The standpoint is brought forth that of primary interest should be
regarded only three specifically distinctive solutions -- one for every curved
space background. In the framework of those arguments the generally accepted
status of the known monopole BPS-solution should be critically reconsidered and
even might be given away.Comment: 7 page
Geometry of 3-Spaces with Spinor Structure
A special approach to examine spinor structure of 3-space is proposed. It is
based on the use of the concept of a spatial spinor defined through taking the
square root of a real-valued 3-vector. Two sorts of spatial spinor according to
P-orientation of an initial 3-space are introduced: properly vector or pseudo
vector one. These spinors, \eta and \xi, turned out to be different functions
of Cartesian coordinates. To have a spinor space model, you ought to use a
doubling vector space. The main idea is to develop some mathematical technique
to work with such extended models. Two sorts of spatial spinors are examined
with the use of curvilinear coordinates (y_{1},y_{2},y_{3}): cylindrical
parabolic, spherical and parabolic ones. Transition from vector to spinor
models is achieved by doubling initial parameterizing domain
G(y_{1},y_{2},y_{3}) \Longrightarrow \tilde{G}(y_{1},y_{2},y_{3}) with new
identification rules on the boundaries. Different spinor space models are built
on explicitly different spinor fields \xi(y) and \eta(y). Explicit form of the
mapping spinor field \eta(y) of pseudo vector model into spinor \xi(y) of
properly vector one is given, it contains explicitly complex conjugation.Comment: 36 pages, 31 figure
Spinor Structure of P-Oriented Space, Kustaanheimo-Stifel and Hopf Bundle - Connection between Formalisms
In the work some relations between three techniques, Hopf's bundle,
Kustaanheimo-Stiefel's bundle, 3-space with spinor structure have been
examined. The spinor space is viewed as a real space that is minimally (twice
as much) extended in comparison with an ordinary vector 3-space: at this
instead of 2\pi-rotation now only 4\pi-rotation is taken to be the identity
transformation in the geometrical space. With respect to a given P-orientation
of an initial unextended manyfold, vector or pseudovector one, there may be
constructed two different spatial spinors, and , respectively. By
definition, those spinors provide us with points of the extended space odels,
each spinor is in the correspondence $2 \longrightarrow 1 with points of a
vector space. For both models an explicit parametrization of the spinors \xi
and \eta by spherical and parabolic coordinates is given, the parabolic system
turns out to be the most convenient for simple defining spacial spinors. Fours
of real-valued coordinates by Kustaanheimo-Stiefel, U_{a} and V_{a}, real and
imaginary parts of complex spinors \xi and \eta respectively, obey two
quadratic constraints. So that in both cases, there exists a Hopf's mapping
from the part of 3-sphere S_{3} into the entire 2-sphere S_{2}. Relation
between two spacial spinor is found: \eta = (\xi - i\sigma ^{2}\xi
^{*})/\sqrt{2}, in terms of Kustaanheimo-Stiefel variables U_{a} and V_{a} it
is a linear transformation from SO(4.R), which does not enter its sub-group
generated by SU(2)-rotation over spinors.Comment: 28 page
On Concept of Parity for a Fermion
The known problem of fermion parity is considered on the base of
investigating possible linear single-valued representations of spinor coverings
of the extended Lorentz group. It is shown that in the frame of this theory
does not exist, as separate concepts, P-parity and T-parity for a fermion,
instead only some unified concept of (PT)-parity can be determined in a
group-theoretical language.Comment: 8 page
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