Showing papers on "Scalar potential published in 1985"
TL;DR: In this article, general properties of N = 2 gauged extended supergravity coupled to vector multiplets are derived, and the scalar potential of the theory which determines the classical vacuum structure is investigated.
336 citations
Journal Article•
TL;DR: In this article, a self-consistent problem involving the behavior of small perturbations in an isotropic homogeneous universe filled with a scalar field is considered and solutions describing the evolution of perturbation in the case of an arbitrary scalar-field potential are obtained.
Abstract: A self-consistent problem involving the behavior of small perturbations in an isotropic homogeneous universe filled with a scalar field is considered Solutions describing the evolution of perturbations in the case of an arbitrary scalar-field potential are obtained
228 citations
TL;DR: In this article, the eddy current equations are formulated in terms of H, instead of the more usual vector potential A, where a combination with a scalar potential is necessary in the non conducting regions.
Abstract: The eddy current equations are formulated here in terms of H [1] instead of the more usual vector potential A [2,3]. In both cases a combination with a scalar potential is necessary in the non conducting regions. In the case of A this leads to either a non symmetric or not positive definite system of equations to be solved. This is avoided by the formulation in H, but special elements have to be chosen in order to satisfy the interface conditions between the two regions. The construction of such elements on tetrahedra or rectangular blocks can be found in [4]. The construction for hexahedra, or more specifically, isoparametric bricks, is shown here. Compared to filling a hexahedron with tetrahedra, this method reduces the number of unknowns by a half. The computed approximations for the eddy currents are exactly non divergent.
99 citations
TL;DR: In this paper, the scalar potential to two-loop order was shown to vanish for an appropriate redefinition of the potential, and the R -dependence of the β-function for the potential to 2-loop orders was shown.
36 citations
TL;DR: In this article, a 3D magnetic field calculation method was proposed, when there are iron-air laminations in the domain, and applied to a variational finite element method, using a scalar potential.
Abstract: We propose, in this paper, a 3D magnetic field calculation method, when there are iron-air laminations in the domain. This model is applied to a variational finite element method, using a scalar potential. The iron non-linearity is considered and a Newton-Raphson method for this 3D anisotropic problem is developed.
31 citations
TL;DR: The paper describes the development of 3-dimensional scalar potential finite-element solvers, starting with the straightforward magnetostatic/ electrostatic case, then extended to include the effect of eddy currents by the surface impedance method, and finally, the full 2-dimensional eddy current problem is tackled using the 3T-Ω approach.
Abstract: In order to design electrical equipment to meet normal and abnormal operating conditions reliably and with economy in materials, advanced computational aids are needed. This has led to the development of 3-dimensional electromagnetic/electrostatic solvers capable of modelling non-linear materials and, in the electromagnetic case, eddy currents. The paper describes the development of 3-dimensional scalar potential finite-element solvers, starting with the straightforward magnetostatic/ electrostatic case. This solver is then extended to include the effect of eddy currents by the surface impedance method, and finally, the full 3-dimensional eddy current problem is tackled, using the 3T-Ω (the vector electric potential-scalar magnetic potential) approach. Examples of practical applications are given, and experience with ICCG routines discussed.
20 citations
01 Aug 1985
TL;DR: In this paper, a scalar/vector potential formulation for viscous compressible flows is presented, based on the classical Helmholtz decomposition of any vector field into the sum of an irrotational and a solenoidal field.
Abstract: A scalar/vector potential formulation for unsteady viscous compressible flows is presented. The scalar/vector potential formulation is based on the classical Helmholtz decomposition of any vector field into the sum of an irrotational and a solenoidal field. The formulation is derived from fundamental principles of mechanics and thermodynamics. The governing equations for the scalar potential and vector potential are obtained, without restrictive assumptions on either the equation of state or the constitutive relations or the stress tensor and the heat flux vector.
16 citations
DOI•
01 Jul 1985TL;DR: Complementary functionals, expressed in terms of either E and? × E or H and H × H, applying to linear eddy-current problems are given and are shown to be stationary subject to simple, and sometimes natural, boundary constraints as mentioned in this paper.
Abstract: Complementary functionals, expressed in terms of either E and ? × E or H and ? × H, applying to linear eddy-current problems are given and are shown to be stationary subject to simple, and sometimes natural, boundary constraints. The analysis is carried through to a late stage before the pre-Maxwell zero-displacement current approximation is applied, in order not to obscure the principal results. The extension to a laminated media is considered. Representation of the quasistatic H-field in any current-free region of the problem by a scalar potential is allowable. The results are verified by perturbing the known `skin effect? quasi-static solution for parallel busbars. It is suggested how real eddy-current problems might be tackled by using the finite-element matrices for tetrahedral elements which have been derived by previous authors to apply to high-frequency problems and to the scalar Helmholtz equation.
14 citations
TL;DR: In this article, the authors consider the linearized scalar potential formulation of the magnetostatic field problem in a parametric framework and show that the field in the exterior of a sphere is expanded in a harmonic series of eigenfunctions for the exterior harmonic problem.
11 citations
TL;DR: In this paper, a superfield formulation of a particle with spin and anomalous magnetic moment interacting with an electromagnetic field and a scalar potential is presented, where the fermion superfield ''sigma'' is introduced to form the mass term of the superparticle.
Abstract: This paper presents a superfield formulation of the action of a particle with spin and anomalous magnetic moment interacting with an electromagnetic field and a scalar potential. A feature of the superfield formulation is the use of the fermion superfield ''sigma'', introduced to form the mass term of the superparticle.
10 citations
TL;DR: In this paper, an equivalent magnetized region solution based on scalar potential for solving 3D magnetostatic fields is presented, where the current distribution is transformed into a region of magnetic dipoles, and only one potential is used to calculate the field.
Abstract: A new method "Equivalent Magnetized Region Solution" based on scalar potential for solving 3D magnetostatic fields is presented. The current distribution is transformed into a region of magnetic dipoles and only one scalar potential is used to calculate the field. A program "CMF3D" has been developed by finite element method, equipped with program "MESH" for subdividing field region into elements. Three examples by the solution are presented and compared with results from analytical method or experiment.
TL;DR: In this article, the conditions under which gravity can stabilize otherwise metastable or unstable scalar field configurations were derived using the formalism of Boucher and derived the stability criteria first obtained by Coleman and DeLuccia.
TL;DR: In this article, the Preisach hysteresis model is implemented into the finite element method, which is well suited to a scalar potential representation of the field, a fact that has not been fully appreciated so far.
Abstract: The Preisach hysteresis model is implemented into the finite element method. It is demonstrated that this model is well suited to a scalar potential representation of the field, a fact that has not been fully appreciated so far. Although this clearly eliminates the possibility of dealing exactly with problems involving eddy currents in hysteretic subregions, the computation of the magnetic field when both hysteretic and nonmagnetic current‐carrying subregions are present simultaneously can be handled by adopting a hybrid formulation. This allows complete field solutions in reactor or transformer problems. Finally, it is shown how position‐dependent remanent magnetization can be dealt with in a straightforward manner, without the need to use both volume and surface elements simultaneously, and without any assumption on the order of the interpolation polynomials for the potential. The method is also applicable to permanent magnet problems for which an accurate representation of the spatial dependence of rem...
TL;DR: In this article, a volume integral method is used with the finite element technique as a differential numerical approach to predict the levitating force acting on a E core plate levitator and the results were in good agreement with the experimental measured values.
Abstract: The solution of the electromagnetic field in any electromagnetic device is best appreciated if expressed in terms of the terminal characteristics of the device, namely forces. In this paper expressions for force calculations are derived from the numerical field solutions in terms of \bar{T} -the electric vector potential and Omega(Ω)-the magnetic scalar potential. The volume integral method is used with the finite element technique as a differential numerical approach. The technique was tested to predict the levitating force acting on a E core plate levitator and the results were in good agreement with the experimental measured values.
TL;DR: In this paper, the scalar potential of axisymmetric conductors can be expressed as a Legendre polynomial expansion, and a method is presented for augmenting the expansion coefficients to include the effects of iron of constant permeability on the system.
Abstract: The scalar potential of any system of axisymmetric conductors can be expressed as a Legendre polynomial expansion, and this provides an efficient and convenient method for computing the field variables. A method is presented for augmenting the expansion coefficients to include the effects of iron of constant permeability on the system. The approach is based on the boundary element method (BEM). As well as giving physical insight into the effects of the iron, the use of the coefficients circumvents the problem of expensive field retrieval. Numerical accuracy is assessed by considering two geometries for which an exact solution is known.
TL;DR: In this paper, the dynamics of a Bloch electron in a spatially uniform electric field is investigated by employing a vector potential to represent the effect of the field on the electron dynamics.
Abstract: The dynamics of a Bloch electron in a spatially uniform electric field is investigated by employing a vector potential to represent the effect of the field. This method has the advantage of maintaining the translational periodicity of the Hamiltonian in the presence of the field, and avoids the difficulties associated with the use of a scalar potential. We find that both the tunneling probability to other bands and the ladder-like structure in the optical absorption are obtained without any assumption concerning the existence of Wannier-Stark energy levels.
Journal Article•
TL;DR: The modified fictitious magnetic monopole model (FMMM) as mentioned in this paper is a modification of the two-scalar potential model for 3D magnetostatic field problems, in which a new kind of scalar potential is used for the whole region, including the distributed current region.
Abstract: In this paper the authors present a new model for magnetostatic field problems - the modified fictitious magnetic monopole model, in which a new kind of scalar potential is used which is suitable for the whole region, including the distributed current region. In the FMMM the exciting action of the distributed current density has been replaced by that of a distributed fictitious magnetic monopole density, and the problem of loss of precision (subtraction of two large but similar quantities in the computer) has been solved by putting a magnetic shell into the coil and/or current-carrying conductor loop. According to the new model, the formulation of a magnetostatic problem has almost the same form as that of an electrostatic problem, thus the calculation of magnetostatic problems can be simplified significantly. The new model can also be regarded as a modification for the two-scalar potential model or for the T-Q method in magnetostatic cases. Calculation and test results of some examples of 3D magnetostatic problems are given to verify this new method.
TL;DR: The Lorentz scalar potential as mentioned in this paper gives rise to a fourth component of the relativistic four-force which has a different form than that of the vector interaction, the difference arising from the variable mass for particles interacting through the Scalar potential as compared to the constant mass for particle interactions through the vector potential.
Abstract: The Lorentz scalar interaction gives rise to a fourth component of the relativistic four‐force which has a different form than that of the vector interaction, the difference arising from the variable mass for particles interacting through the scalar potential as compared to the constant mass for particles interacting through the vector potential. The Lorentz scalar potential, with its pedagogically interesting dynamics, is rarely mentioned in intermediate‐level or first‐year, graduate‐level textbooks.
TL;DR: In this paper, the authors derived the magnetic field with the aid of magnetic scalar potential for a four-coil system of spherical harmonics under rotation, where the transformation properties of spherical harmonic under rotation were used to analyze the magnetic fields of a system of several coils.
Abstract: A derivation of the magnetic field, created by rectangular single‐turn coils, is achieved with the aid of magnetic scalar potential. The transformation properties of spherical harmonics under rotation permit one to analyze the magnetic field of a system of several coils. Application to a four, rectangular coil system, generating a magnetic field gradient, leads to the optimal dimensions of each element of the system: h=1.732, b=2.486, when a=1 and β=45°, where a represents the half‐width of the rectangle, b its half‐length, h the distance between the origin of the reference frame and the center of each coil, and β is the angle between the directions of the normals to the planes of two neighboring coils.
TL;DR: In this article, Scalar field equations are developed on the assumption that a nucleons mass is stored in its surrounding Yukawa field, and the AIP equations are derived on this assumption.
Abstract: Scalar field equations are developed on the assumption that a nucleons mass is stored in its surrounding Yukawa field. (AIP)
TL;DR: A review of recent developments on the quark descriptions of nuclear forces can be found in this article, where a nuclear scalar potential applied directly to quarks in nucleons in nuclear matter reduces quark masses, decreases the nucleon axial charge, and increases the Δ-N splitting.
IBM1
TL;DR: In this article, a new right-hand side of the integral equation is formulated in simple terms to obtain the rate of change in potential due to a change in the position of an electrode or magnet polepiece.
Abstract: In the computer design of electric and magnetic devices, when the fields can be derived from a scalar potential satisfying the Laplace equation, integral equation methods are powerful tools, particularly in 3-d problems. A certain Fredholm integral equation of the first kind, used first to obtain the potential, may be utilized a second time with a different right-hand side to obtain directly the rate of change in potential due to a change in the position of an electrode or magnet pole-piece. The new right-hand side of the integral equation is formulated in simple terms. Knowledge of this rate of change suggests itself to two types of applications: alignment sensitivity study and improved numerical optimization of electromagnetic devices.
TL;DR: In this paper, the authors derived implicit dispersion relations for both surface and bulk modes, along with numerical calculations for MnF2 and GdAlO3, and found that the application of a magnetic field strongly localized the surface spin wave to either the top or bottom surface of the film.
Abstract: We discuss antiferromagnetic bulk and surface spin waves, in the long‐wavelength region, on a finite thickness slab geometry. Implicit dispersion relations for both surface and bulk modes are derived, along with numerical calculations for MnF2 and GdAlO3. In the absence of a magnetic field the magnetic scalar potential has either pure even or pure odd symmetry. We find that the application of a magnetic field strongly localizes the surface spin wave to either the top or bottom surface of the film. In addition we will discuss the propagation of spin waves localized at the interface between a ferromagnet and an antiferromagnet.