Photon propagator,monopoles, and the thermal phase transition in three dimensional compact QED

We investigate the gauge boson propagator in the three dimensional compact Abelian gauge model in the Landau gauge at finite temperature. The presence of the monopole plasma in the confinement phase leads to the appearance of an anomalous dimension in the momentum dependence of the propagator. The anomalous dimension as well as an appropriate ratio of photon wave function renormalization constants with and without monopoles is observed to be an order parameter for the deconfinement phase transition. We discuss the relation between our results and the confining properties of the gluon propagator in non-Abelian gauge theories.     

Towards Abelian-like formulation of the dual gluodynamics

We consider gluodynamics in case when both color and magnetic charges are present. We discuss first short distance physics, where only the fundamental |Q_m|=1 monopoles introduced via the 't Hooft loop can be considered consistently. We show that at short distances the external monopoles interact as pure Abelian objects. This result can be reproduced by a Zwanziger-type Lagrangian with an Abelian dual gluon and ordinary gluons in an adjoint representation. We introduce also an effective dual gluodynamics which might be a valid approximation at distances where the monopoles |Q_m|=2 can be considered as point-like as well. Assuming the monopole condensation we arrive at a model which is reminiscent in some respect of the Abelian Higgs model but, unlike the latter leaves space for the Casimir scaling.     

统一场论中的磁单极

本文的主要目的是介绍磁单极理论的基本结果。 我们首先介绍Dirac磁单极的基本思想。然后,进一步评述统一场论中的拓扑磁单极,并说明磁单极在早期宇宙中是怎种产生的。最后,我们讨论磁单极问题上最惊人的现象——磁单极对核子衰变的催衰化作用及其温度依赖关系。     

Longitudinal plasma waves in the presence of monopoles of electron mass and electron charge

Dispersion relation for plasma waves in the presence of magnetic monopoles of electron mass and electron charge, is derived. It is shown that magnetic monopole charges, in general, dominate the dispersion. When monopoles form a fraction of the main body of plasma, there are two dominant oscillations. It is suggested that there can be electromagnetic emissions at these frequencies by nonlinear conversions. Possible application to the pulsar neighbourhood is envisaged.     

电磁学与电动力学中的磁单极-Ⅱ

本系列文章一共4篇,在电磁学和电动力学框架内用尽量科普的方式分别介绍磁单极的若干奇特性质.本篇文章主要介绍狄拉克磁单极是如何展示矢量势的规范变换的.我们首先简要介绍规范变换与规范对称性及狄拉克磁单极与狄拉克弦,然后讨论狄拉克磁单极与规范变换的联系.我们显式演示狄拉克弦摆动产生的规范变换,弦摆动区域对场点所张的立体角正比于规范变换的变换函数.磁偶极子则可以由两个无穷靠近的正反狄拉克磁单极构成.相应两条狄拉克弦位置的变化都对应磁偶极子矢量势的规范变换,特别当两条弦重合时弦效应相互抵消,只剩下纯的磁偶极子.传统的由磁偶极子产生的矢量势的规范变换则可以图像化为组成磁偶极子的正反狄拉克磁单极的狄拉克弦的摆动.我们显式地计算了位于坐标原点弦为直线的狄拉克磁单极,并进一步构造了没有奇异的吴大峻-杨振宁磁单极.     

Exact magnetic monopole solutions in Yang-Mills and unified gauge theories

We study the magnetic monopoles in non-Abelian gauge theories. The exact static, spherically symmetric solutions of the magnetic monopoles in both Yang-Mills and unified gauge theories are obtained. The energyE of the static system is calculable and it is either zero or infinite. The existence of the magnetic monopole solution is a consequence of symmetry rather than dynamics. We propose a new definition of the electromagnetic field tensor, which relates the static solution of gauge fields and the magnetic monopole solution. Experimental implications are discussed.     

Kertész line and embedded monopoles in QCD

We propose a new class of defects in QCD which can be viewed as embedded monopoles made of quark and gluon fields. These objects are explicitly gauge invariant and they closely resemble the Nambu monopoles in the standard electroweak model. We argue that the "embedded QCD monopoles" are proliferating in the quark-gluon plasma phase while in the low-temperature hadronic phase the spatial proliferation of these objects is suppressed. At realistic quark masses and zero chemical potential the hadronic and quark-gluon phases are generally believed to be connected by a smooth crossover across which all thermodynamic quantities are nonsingular. We argue that these QCD phases are separated by a well-defined boundary-known as the Kertész line in condensed matter systems-associated with the onset of the proliferation of the embedded QCD monopoles in the quark-gluon plasma phase.     

Torsional Weyl-Dirac Electrodynamics

Issuing from a geometry with nonmetricity and torsion we build up a generalized classical electrodynamics. This geometrically founded theory is coordinate covariant, as well as gauge covariant in the Weyl sense. Photons having arbitrary mass, intrinsic magnetic currents, (magnetic monopoles), and electric currents exist in this framework. The field equations, and the equations of motion of charged (either electrically or magnetically) particles are derived from an action principle. It is shown that the interaction between magnetic monopoles is transmitted by massive photons. On the other hand, the photon is massive only in the presence of magnetic currents. We obtained a static spherically symmetric solution, describing either the Reissner-Nordstrom metric of an electric monopole, or the metric and field of a magnetic monopole. The latter must be massive. In the absence of torsion and in the Einstein gauge one obtains the Einstein-Maxwell theory.     

由正负磁单极对相互作用诱导的孤立狄拉克弦

基于三维旋量Gross-Pitaevskii(GP)方程研究在含时周期性外磁场作用下玻色-爱因斯坦凝聚体的动力学行为.结果显示,在含时周期外磁场的作用下,铁磁态自旋为1的玻色-爱因斯坦凝聚体将发生拓扑形变.当磁场的两个零点进入凝聚体后,自旋向上态的密度布居图在z轴上分别形成向上和向下的凸起.随着磁场的两个零点在凝聚体内逐渐重合,向上和向下的凸起被拉长,最终自旋向上态在z轴上呈线状分布,这与理论分析预测得到的孤立狄拉克弦相对应.最后,通过计算凝聚体的超流涡度给出磁单极的表征图.结果显示,凝聚体在磁场的两个零点处形成正、负磁单极对,分别对应着自旋向上态在z轴上向上和向下的凸起.随着磁场的两个零点重合,正、负磁单极对中的两条狄拉克弦逐渐靠近,之后大约经5 ms,它们完全相连,最终形成孤立的狄拉克弦.     

Interactions of magnetic monopoles with nuclei and atoms: Formation of bound states and phenomenological consequences

We discuss the binding of magnetic monopoles to nuclear and atomic systems. The energy spectrum is calculated, by assuming an interaction with a hard core. The formation process of monopole-nucleus bound states is analysed and it is shown that monopoles reaching Earth are most likely bound to a proton. We also discuss phenomenological implications of the existence of bound states in connection with the monopole catalysis of proton decay.     

Magnetic monopoles: Evidence since the Dirac conjecture

In the fifty-one years since its publication Dirac's magnetic monopole conjecture has stimulated a theoretical outpouring rich in variety. We review here the experimental techniques with which monopoles have been sought and we will describe the limits on monopole properties these searches have established.     

Search for magnetic monopoles with the nuclear track detector of the MACRO experiment at gran SASSO

In this paper the limits are presented which were obtained by the search for magnetic monopoles using the MACRO track-etch subdetector as a stand alone detector. We compare the flux upper limit for g = g_D monopoles to other limits obtained by different subdetectors of MACRO, till August 1, 1995, when the construction of the apparatus was completed. The global MACRO monopole limit is compared with other limits from different experiments.     

Search for GUT magnetic monopoles and nuclearites with the MACRO experiment

We present the final results obtained by the MACRO experiment in the search for GUT magnetic monopoles and nuclearites. Several searches were performed with different subdetectors, i.e. scintillation counters, limited streamer tubes and nuclear track detectors. No magnetic monopole or nuclearite candidates were found. The MACRO upper limit to the local flux of GUT magnetic monopoles is at the level of 1.4×10⁻¹⁶ cm⁻² s⁻¹ sr⁻¹.     

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.     

磁荷对中子星质量半径比的约束

讨论了荷电(磁)质点的量子力学波方程及其解. 由磁场中解的奇异性讨论了磁单极的存在; 由Rubakov-Callan模型推知中子星可能含有大量磁单极. 然后采用中子星的结构方程, 讨论了磁荷对中子星质量半径比的约束, 分别得到了磁荷对中子星质量半径比上限的影响 和磁荷对中子星质量半径比下限的影响的数学表达式. 关键词： 磁单极 中子星 质量半径比     

Hamiltonian nature of monopole dynamics

Classical electromagnetism with magnetic monopoles is not a Hamiltonian field theory because the Jacobi identity for the Poisson bracket fails. The Jacobi identity is recovered only if all of the species have the same ratio of electric to magnetic charge or if an electron and a monopole can never collide. Without the Jacobi identity, there are no local canonical coordinates or Lagrangian action principle. To build a quantum field of magnetic monopoles, we either must explain why the positions of electrons and monopoles can never coincide or we must resort to new quantization techniques.     

Nambu-Jona-Lasinio version of magnetic monopole physics with dual Dirac strings

We propose a model where a condensate of monopole-antimonopole pairs leads to confinement. Magnetic monopoles are considered as massless fermion fields interacting via local four-monopole interaction of the Nambu-Jona-Lasinio kind leading to monopole condensation. Condensation of magnetic monopole currents and any derivative of them are obtained. It is shown that the bosonized version of this Monopole Nambu-Jona- Lasinio (MNJL) model is reducing to London’s theory of dual superconductivity within Dirac’s extension of Maxwell’s Electrodynamics. The affinity of the MNJL-model with Compact Quantum Electrodynamics is discussed.     

On a core instability of ''t Hooft–Polyakov type monopoles

We discuss a core instability of 't Hooft–Polyakov monopoles in Alice electrodynamics type of models in which charge conjugation symmetry is gauged. The monopole may deform into a toroidal defect which carries an Alice flux and a (non-localizable) magnetic Cheshire charge.     

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.