Magnetic Monopole Model Research Articles

Magnetic monopoles in quantum adiabatic dynamics and the immersion property of the control manifold

It is well known that the Berry phase of a cyclic adiabatic dynamical system appears formally as the flux of a magnetic field in the control parameter manifold. In this electromagnetic picture a level crossing appears as a Dirac magnetic monopole in this manifold. We make an extensive study of the magnetic monopole model of eigenvalue crossings. We show that the properties of the monopole magnetic field in the control manifold are determined by the immersion of the control manifold in a space given by the universal classifying theorem of fiber bundles. We give a detailed illustrative study of the simple but instructive case of a two level crossing of a system controlled by a two-dimensional manifold.

A computer simulation to help in teaching inductionphenomena

The motion of a magnet through a coil is analysedthrough a model of magnetic monopoles. The magnetic flux of amonopole passing through a loop is explained and also its rate ofchange. By a superposition of voltages produced by the monopoleson the coils the shape of the voltage versus time graph is explained.Also examined is the interaction of a magnet moving through aloop and the fall of a magnet through a solenoid, or independentloops and the fall of the magnet in a metal pipe. This software can help thestudent to apply principles of mechanics and improveunderstanding of graphs.

Alfven wave transmission through the solar atmosphere

The transmission and reflection coefficients of shear Alfven waves in an open magnetic structure emerging from the Sun are determined. Both two-dimensional slab and axisymmetric static equilibrium configurations are solved numerically on a curvilinear coordinate grid adapted to the magnetic field geometry and to the density stratification. The equilibrium structure obtained numerically extends from the photosphere up to an altitude of 20,000 km, spanning 14 density scale heights and allowing for a magnetic flux tube expansion by a factor 40-400, corresponding to a filling factor of 2.5% to 0.25%. From 20,000 km up to 4 R ⊙ a magnetic monopole model is adopted

3D finite element solution of complex magnetostatic problem involving axial and radial excitation-using a single scalar potential

The fictitious magnetic monopole model (FMMM) of motors having a complex magnetostatic field excited by both axial (permanent) and radial current is established. A single scalar potential is used to derive a precise solution of the 3-D anisotropic nonlinear rotational field in such a motor. The 3-D FEM (finite-element method) solution is used to modify the conventional '2-D field-circuit' calculation model. >

Determination of the current-equivalent parameters for the fictitious magnetic monopole model of magnetostatic problems

Some principles for determining the current-equivalent parameters in the fictitious magnetic monopole model (FMMM) of magnetostatic problems are presented that can be used to overcome the difficulty related to applying the FMMM in problems with complex-shaped current-carrying conductors. DC coils with different shapes have been analyzed, and the results have been used directly in the calculation of practical examples. Calculated and experimental results show the validity of these principles. >

Finite element solution of 3D magnetostatic field problems involving distributed current using a single scalar potential--The modification and application of the fictitious magnetic monopole model

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.

High-energy cusp in the magnetic-monopole model of the hadron

It is shown that, in the magnetic-monopole model of the hadron, the same mechanism which leads to the strong van der Waals force between hadrons also gives rise to an extra singularity att=4M4/s in the absorptive part of the scattering amplitudeAs(s, t). The effect of such a singularity is to be observed in the forward region in high-energy scattering. The high-energy π-p data are analysed in search of the singularity. After separating the singularity due to the ordinary Coulomb interaction, we find a cusp ofAs(s, t) att=0 which points upward, in agreement with the prediction of the magnetic-monopole model of the hadron.

Interaction of flux tubes in a type I superconductor

The repulsive interaction between multiquantum flux tubes in type I superconducting lead films has been studied magnetooptically. Two or three flux tubes were trapped in a long and narrow region of slightly reduced film thickness, and the flux tube positions were recorded as a function of an applied Lorentz force pressing the tubes against each other. At distances larger than about the flux tube diameter our results agree well with the magnetic monopole model, which only takes into account the magnetic stray field outside the superconducting film. At smaller distances deviations from the monopole model occur due to the influence of the cross-sectional shape of the flux tubes and of the wall of the tubes upon the energy of the flux tube configuration. These influences have been taken into account by means of a subdivision model in which the flux-containing region of each tube is divided into a large number of flux portions each of which is approximated again by a magnetic monopole. For sufficiently high compression due to the Lorentz force, we have observed fusion of two individual flux tubes. Upon reduction of the Lorentz force, the fused flux tubes separate again. The process of fusion and separation shows distinct hysteresis. This behavior is also well explained by our subdivision model.

High-precision p-p scattering at low energy and the magnetic-monopole model of hadron

High-precision measurements of the differential crosssection dΣ/dΩ of the proton-proton scattering at a fixed incident energy in the range 10 MeV <T < 30 MeV are proposed. The purpose is to observe the effect of the strong van der Waals force, which is expected to occur in the magnetic-monopole model of the hadron, between the protons. Due to the long-range nature of the strong van der Waals force, such an effect is most prominent at small angles and, therefore, measurements should be carried out down to θ ~ 12‡. The required precision is 0.3% atT = 25 MeV in the relative errors.

Strong van der Waals potential in πN scattering

Low-energy data of pion-nucleon scattering are analysed in search of the effect of the strong van der Waals force, whose appearance has been expected in the magnetic-monopole model of hadrons. After separating the spectra arising from the exchanges of hadrons, an extra potentialVextra(r) is determined forrμ > 1.3. Vextra(r) changes sign from repulsive to attractive at rμ = 1.55, asr increases. Vextra(r) has a minimum atr/gm = 1.9 and its value is - 1.1 MeV. The similarity betweenVextra(r) and the potential of the ordinary atom-atom interaction is pointed out.

Proposal to Confirm the Strong van der Waals Interaction in Low Energy p-p Scattering

It is shown that the low energy P·P data, especially the Wisconsin data, already indicate the existence of the strong long range force acting between the nucleons, which is expected to occur in the magnetic monopole model of hadrons. In arriving at the conclusion, the detailed information concerning the two-pion exchange spectrum is not required. It is pro­ posed to measure accurately the angular distribution of proton-proton scattering at low energy (0.1 MeV ;ST;S25 MeV), and to estimate the power /3 of the long range tail of the ,

Regular solution of 't Hooft's magnetic monopole model in curved space

A regular solution of 't Hooft's magnetic monopole model in curved space is presented. As in flat space, an analytical solution seems impossible, but by using the Einstein equations to eliminate the gravitational degrees of freedom, a positive-definite energy functional is constructed, which at its minimum gives both the required solution and the energy of the system. To first order in the gravitational constant $G$, the energy can be expressed in terms of the flat-space solutions only, whereas for general $G$ a positive lower bound is derived.

The nuclear force and a magnetic monopole model of hadrons

The two-pion exchange potential of the nuclear force is constructed from the phase shifts of the low energy πN and ππ scattering. The large difference between the potentials thus constructed from the phenomenological potentials of Hamada-Johnston and of Bryan is pointed out. It is found that this difference has the form of the attractive Van der Waals potential plus an inner repulsive core. The existence of the Van der Waals force is discussed in connection with the magnetic monopole model of hadrons.