Majumdar-Papapetrou class of nonstatic cylindrically symmetric Brans-Dicke-Maxwell fields

We have obtained relations between certain components of the metric and the electromagnetic potentials for source-free Brans-Dicke-Maxwell fields described by a nonstatic cylindrically symmetric Einstein-Rosen metric. These are important, in the sense that they generate a class of solutions that in a way can be said to belong to the class generated by similar relations obtained by Majumdar [1] and Papapetrou [2] for generalized static Einstein-Maxwell fields. The relations have further been used to reduce the B-D Maxwell equations to B-D vacuum equations and vice versa.     

Generation of radially polarized mode using an active cylindrically symmetric birefringence fiber

A class of active fiber is presented as gain mediums of fiber lasers, where a silica layer with spoke-like air slits is introduced between the active core and cladding to obtain birefringence. With an appropriate choice of the design parameters, the fiber can support only the HE₁₁ and TM₀₁ modes. Furthermore, the numerical results show that, corresponding to the optimal rare earth doping profile, the fiber lasers can output a pure TM₀₁ mode with about 79% slope efficiency without using other mode-selective elements.     

Resonance cones in cylindrically anisotropic metamaterials: a Green's function analysis

A Green's function analysis for cylindrically anisotropic media is presented that can be used in the design of various metamaterial devices. The resonance cones, which describe the direction of power flow, result from the Green's function singularity when the permittivity tensor elements have opposite signs. Shadow and accessible regions for the source are also identified.     

Generation of cylindrically symmetric magnetic fields with permanent magnets and µ-metal

A method that allows the calculation of magnetic fields produced by cylindrically symmetric configurations of permanent magnets and high permeability materials is presented. The method is based on a non-iterative finite-element algorithm and can be utilized on small-scale computing facilities. As an example, the design of a magnetic trap for neutral atoms is discussed. Comparisons of calculations with analytical and experimental data are also reported.     

Iterative abel inversion of optically thick,cylindrically symmetric radiation sources

An inversion algorithm for obtaining the radial emission and absorption coefficients of a cylindrically symmetric radiation source from transverse profiles of monochromatic radiance and absorptance is described and compared with the algorithm of Elder et al. It is shown that the present method converges to the correct solution, whereas that of Elder et al. does not.     

On the dyadic Green's functions for Beltrami fields

A simple derivation of the Green's functions for Beltrami fields is presented for use with time-harmonic electromagnetism in homogeneous biisotropic media.     

Green's function of a generalized Dirac equation for constant fields

Schwinger's method is used to find the Green's function for a Dirac equation in which the presence of anomalous moments of the fermion is taken into account phenomenologically and constant and homogeneous electromagnetic fields are assumed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 70–75, November, 1980.     

On symmetric gauge fields

The subgroups of the symmetry group of the gauge invariant Lagrangian are studied. For given subgroupG theG-invariant gauge fields are listed.     

Linearization procedure for cylindrically and axially symmetric space-times

An investigation of the vacuum Einstein gravitational field equations for cylindrically and axially symmetric space-times is presented which leads to an equivalent differential system involving a simple nonlinearity only. The case when this equivalent system is linear is analyzed in detail and two methods for generating solutions of the Einstein vacuum equations are set up. As a result, in the axially symmetric case the linearity of the equivalent system characterizes completely the Kramer-Neugebauer transforms of Papapetrou line elements. Accordingly, Weyl solutions are shown to generate exhaustively both Lewis and van Stockum solutions. Analogous results are obtained also in the cylindrically symmetric case.     

Structure scalars for charged cylindrically symmetric relativistic fluids

We investigate some structure scalars developed through Riemann tensor for self-gravitating cylindrically symmetric charged dissipative anisotropic fluid. We show that these scalars are directly related to the fundamental properties of the fluid. We formulate dynamical-transport equation as well as the mass function by including charge which are then expressed in terms of structure scalars. The effects of electric charge are investigated in the structure and evolution of compact objects. Finally, we show that all possible solutions of the field equations can be written in terms of these scalars.     

Natural shaping of the cylindrically polarized beams

We have experimentally and theoretically shown that the circularly polarized beam bearing a singly charged optical vortex propagating through a uniaxial crystal can be split after focusing into the radially and azimuthally polarized beams in the vicinity of the focal area provided that the polarization handedness and the vortex topological charge have opposite signs.     

Simple solutions of relativistic hydrodynamics for cylindrically symmetric systems

Simple, self-similar, analytic solutions of 1+3-dimensional relativistic hydrodynamics are presented for cylindrically symmetric fireballs corresponding to central collisions of heavy ions at relativistic bombarding energies.     

On the spherically symmetric gauge fields

The spherically symmetric gauge fields with a compact gauge group over 4-dimensional Minkowski space are determined completely. Expressions for the gauge potentials of these fields are obtained.     

Euclidean Green's functions for Jaffe fields

We extend the axioms for Euclidean Green's functions recently proposed by Osterwalder and Schrader to Jaffe fields.     

Radiation pattern of cylindrically symmetric scalar Laguerre-Gauss beams

The exact full-wave generalization of the cylindrically symmetric scalar real-argument Laguerre-Gauss beam is determined. The radiation intensity of the resulting Laguerre-Gauss wave is deduced, and the main characteristics of the radiation intensity pattern are described. The total power P(n) is evaluated, where n is the radial mode number. By the use of 1/P(n) as the quality parameter, the characteristics of the quality of the paraxial beam approximation to the full Laguerre-Gauss wave are discussed.     

A simple computational method for internal polarized radiation fields of finite slab atmospheres

An extended doubling method is formulated, which provides together with the emergent radiation also the internal polarized radiation field without additional iterations. Two sets of linear regular integral relations are derived, which have to be fulfilled by the surface Green's function matrix or, equivalently, by the Stokes vector of the slab albedo problem radiation field. The integral relations refer to the half range angular variable of the direction of incidence and to the full range angular variable of the direction of light propagation, respectively.     

Static cylindrically symmetric solution of the Kaluza-Klein equations

In this paper we investigate the (static) solution of the Kaluza-Klein equations for a cylindrically symmetric current distribution. Specifically, we are interested in the fields generated by a long, cylindrical solenoid. We shall examine in some detail the concept of effective mass of a charged test particle. We shall show that, for a certain charge-to(rest)mass ratio of the test particle, the effective mass becomes imaginary at a certain distance from the axis of our solenoid.