Anomalous monopoles of an interacting boson system

Two anomalous monopoles, one of line shape and the other of disk shape, are found to exist in the semiclassical theory of a two-mode interacting boson system. This is in stark contrast with the quantum theory of this system, where only point-like monopoles exist. We show that these two anomalous monopoles have different origins. The line-shaped monopole is formed from the merging of a series of point-like monopoles while the disk-shaped monopole is the result of the collapsing or bundling of field lines of Berry curvature due to the existence of the influence of the interaction between bosons. The relation of these two anomalous monopoles with the famed von Neumann-Wigner theorem is discussed.     

A finite free energy density inSU(2) pure Yang-Mills thermodynamics

We show how monopoles, which are stabilized by quantum fluctuations and have a massM～T, contribute to yield an infrared finite expansion for the free energy density of Yang-Mills thermodynamics. The leading behaviour of this expansion is consistent with the perturbative one, but in higher orders it does involve both contributions, which are nonanalytic atg ²=0, and additional analytic terms, which are of nonperturbative origin.     

The seed of magnetic monopoles in the early inflationary universe from a 5D vacuum state

Starting from a 5D Riemann flat metric, we have induced an effective 4D Hermitian metric which has an antisymmetric part which is purely imaginary. We have worked an example in which both, non-metricity and cotorsion are zero. We obtained that the production of monopoles should be insignificant at the end of inflation and the tensor metric should come asymptotically diagonal and describing a nearly 4D de Sitter expansion.     

Magnetic monopoles with Zn charges

Under some circumstances magnetic monopoles can be formed with charges which are additive modulo n. We speak of these as monopoles with Z_n charges. The conditions under which such monopoles arise are examined, and illustrated with some specific examples. These monopoles can be produced at intermediate stages of symmetry breakdown and converted at subsequent stages to ones with ordinary additive charges, specified by the group Z ≡ Z_∞. Simultaneously, new light monopoles with n times the Dirac charge can be produced. It is argued that such monopoles may be exempt from the most stringent cosmological bounds, and hence may be easiest to observe.     

Configurations of SO(3) monopoles with multiple magnetic charge

In this paper we consider configurations of monopoles with multiple magnetic charge in nonabelian gauge theory. Explicit gauge transformations are constructed which eliminate the string singularities for single monopoles of multiple magnetic charge, and for an arbitrary number of monopoles lying along a line. The question of finding nonsingular solutions is discussed.     

Platonic Hyperbolic Monopoles

We construct a number of explicit examples of hyperbolic monopoles, with various charges and often with some platonic symmetry. The fields are obtained from instanton data in ${\mathbb{R}^4}$ that are invariant under a circle action, and in most cases the monopole charge is equal to the instanton charge. A key ingredient is the identification of a new set of constraints on ADHM instanton data that are sufficient to ensure the circle invariance. Unlike for Euclidean monopoles, the formulae for the squared Higgs field magnitude in the examples we construct are rational functions of the coordinates. Using these formulae, we compute and illustrate the energy density of the monopoles. We also prove, for particular monopoles, that the number of zeros of the Higgs field is greater than the monopole charge, confirming numerical results established earlier for Euclidean monopoles. We also present some one-parameter families of monopoles analogous to known scattering events for Euclidean monopoles within the geodesic approximation.     

Magnetic charges,inertia, and arrow of time

The prerelativistic concept of inertial mass (as opposed to gravitational mass) is reconsidered in view of a possible relationship between inertia and magnetic (mass) monopoles. Assuming that such fictitious (topological) charges could have developed in the chaotic early cosmology, a physical principle is suggested, based on dissipation of topological charges and decoupling of interactions, which could have governed the onset of inertia and of the arrow of time, and controlled the critical balance between mass density and expansion rate in the FRW universe. In view of the recent accomplishments in the detection of Dirac monopoles, a generalization of the Eötvos experiment is proposed which could shed light on the grand unification regime. A comment is given on the issue of relating the psychological and the cosmological arrows of time.     

Effective magnetic monopoles and universal conductance fluctuations

The observation of isolated positive and negative charges, but not isolated magnetic north and south poles, is an old puzzle. Instead, evidence of effective magnetic monopoles has been found in the abstract momentum space. Apart from Hall-related effects, few observable consequences of these abstract monopoles are known. Here, we show that it is possible to manipulate the monopoles by external magnetic fields and probe them by universal conductance fluctuation measurements in ferromagnets with strong spin-orbit coupling. The observed fluctuations are not noise, but reproducible quasiperiodic oscillations as a function of magnetization direction, a novel Berry phase fingerprint of the magnetic monopoles.     

Galilean invariance and magnetic monopoles

The existence of Dirac monopoles is shown to be incompatible with Galilean invariance. A discussion follows on the interpretation of monopoles physics in a Galilean approximation.     

Screening of the magnetic field by magnetic monopoles in spin ice

The screening of the external magnetic field by magnetic monopoles in spin ice has been considered. The polarization of the magnetic system with moving monopoles has been shown to result in the incomplete screening of the external magnetic field. The static permeability of spin ice and the magnetic-field screening length have been calculated and numerically estimated and the physical meaning of introducing monopoles is discussed.     

Stratifying monopoles and rational maps

A stratification of the moduli space of monopoles and of the space of rational maps into a flag variety is presented. It is shown that the map associating a rational map to a monopole preserves these strata. These strata explain some problems in the intepretation of the parameters of the moduli space in terms of superpositions of fundamental monopoles. This interpretation is not valid on the individual strata. The space of fundamental monopoles is described and shown to be the same as the corresponding space of rational maps.     

Hyperbolic Multi-Monopoles with Arbitrary Mass

On a complete manifold, such as or hyperbolic space , the limit at infinity of the norm of the Higgs field is called the mass of the monopole. We show the existence, on , of monopoles with given magnetic charge and arbitrary mass. Previously, aside from charge one monopoles, existence was known only for monopoles with integral mass (since these arise from U(1) invariant instantons on ). The method of proof is based on Taubes’ gluing procedure, using well-separated, explicit, charge one monopoles. The analysis is carried out in a weighted Sobolev space and necessitates eliminating the possibility of point spectra.     

Branch Processes of Regular Magnetic Monopole

In this paper, by making use of Duan＇s topological current theory, the branch process of regular magnetic monopoles is discussed in detail. Regular magnetic monopoles are found generating or annihilating at the limit point and encountering, splitting, or merging at the bifurcation point and the degenerate point systematically of the vector order parameter field φ（x）. Furthermore, it is also shown that when regular magnetic monopoles split or merge at the degenerate point of field function φ, the total topological charges of the regular magnetic monopoles are stilI unchanged.     

Monopoles connected by strings and the monopole problem

To clarify the status of proposed causality arguments limiting the annihilation rate of monopoles, we present a three-dimensional model for the formation of monopoles connected by strings. The length distribution of the strings has been found using a Monte carlo simulation of the phase transition. The result is that long strings connecting monopoles are exponentially suppressed in agreement with the theoretical predictions of Mitchell and Turok [1]. The implications of our results for the monopole problem are discussed.     

Rings of monopoles with discrete axial symmetry: explicit solution for N=3

It is shown that, in contrast to continuous axial symmetry, discrete axial symmetry admits separated SU(2) monopoles in static equilibrium. The Corrigan-Goddard conditions on the parameters are enormously simplified and for 3 equidistant monopoles are identically satisfied.     

Cosmological Kaluza-Klein monopoles

A solution of a pair of monopoles in 5D Kaluza-Klein theory without matter fields is given. The scale of the internal space is the same as that of the outer space. Its euclidean version is useful for calculating the wave function of the universe with monopoles.     

规范场中单极子的某些研究

单极是规范场的一个内禀拓扑因素,而且单极的拓扑结构已足决定它的运动规律,这无论在阿贝尔或非阿贝尔场都如是。本文对规范场中单极子的基本概念作一个简单的介绍,并稍为涉及孤子单极,和单极在物理世界的可能存在问题。     

Internal structure of the monopoles

The non-abelian monopoles are shown to form linear multiplets under the color reflection symmetry of the original gauge group. This implies that as far as the gauge symmetry is kept unbroken only the singlet combinations of the monopoles may be admitted in the physical sector.     

Magnetic monopoles, alive

We review recent developments in understanding the physics of the magnetic monopoles in unbroken non-Abelian gauge theories. Since numerical data on the monopoles are accumulated in lattice simulations, the continuum theory is understood as the limiting case of the lattice formulation. We emphasize physical effects related to the monopoles. In particular, we discuss the monopole-antimonopole potential at short and larger distances as well as a dual formulation of the gluodynamics, relevant to the physics of the confinement.