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1.
T. Matos 《Annalen der Physik》1989,501(6):462-472
A systematic investigation of the one- and two-dimensional subspaces of the potential space in the projective field theory is made. From the one-dimensional subspaces some stationary charged solutions can be generated. The two-dimensional subspaces have an isometry group SU(1,1) which corresponds to the Einstein equations in vacuum, an O(2,1) group which corresponds to stationary charged solutions with constant scalar field, and an Abelian group which has no counterpart in the Einstein-Maxwell theory.  相似文献   

2.
This paper gives an algorithm for generating solutions of the Einstein field equations which have an irrotational perfect fluid, with equation of statep=, as source, and which admit a two-parameter Abelian group of local isometries. The algorithm is used to derive a variety of new and known spatially homogeneous cosmological models, both tilted and nontilted. However, since the solutions in general only admit two Killing vectors, spatially inhomogeneous models are also obtained. Finally, it is pointed out that the solution generation technique used in this paper is closely related to solution generation techniques that have been used to generate solutions of the source-free Brans-Dicke field equations, and of the Einstein field equations with a massless scalar field as source.  相似文献   

3.
We discuss several field configurations arising from the nonabelian classical field equations of a source-free SU(2)-Yang-Mills system. The quasi-gauge configurations are analyzed and classified according to the solutions of a nonlinear partial-differential equation in two geometrical variables. A comparison is made with the Abelian case, which allows use to assign an electric or magnetic character to these configurations.  相似文献   

4.
The multivortex solutions of (2+l)-dimensional Abelian Higgs model with a Chern-Simons term are stlrrlied. The Bogomol'nyi-type equations and corresponding Weinberg's index theorem have been derived for a sixth-order Higgs potential. The magnetic field is different from that of the Abelian Chern-Simons Higgs model which has no Maxwell term, and has a maximum at the center of the vortex.  相似文献   

5.
The dependence of the effective action for gauge theories on the background field obeys an exact identity. We show that for Abelian theories the Ward identity follows from the more general background field identity. This observation is relevant for the formulation of effective actions with an infrared cutoff since the solution of exact flow equations must obey an anomalous Ward identity.  相似文献   

6.
This paper gives an overview and reviews some recent investigations of anisotropic and inhomogeneous models. A class of models, which admit an Abelian two-parameter group of isometries, is considered in detail. Within this class of models we present exact solutions of the Einstein field equations. These solutions describe inhomogeneous cosmological models containing gravitational, scalar and electromagnetic waves. The solutions are used to study the effect of the symmetry breaking in corresponding Bianchi models. The nonlinear dynamics of primordial inhomogeneities is considered. The global evolution of the inhomogeneous models considered is also investigated. Finally we discuss the validity of various assumptions, used in the earlier treatments of inhomogeneous models.  相似文献   

7.
The equations describing an electromagnetic field, a Yang-Mills massless field, and a free massive vector field are generalized in a quaternion setting. The generalized equations are invariant under a six-parameter group of transformations, which do not affect the space-time coordinates. In application to the generalized Maxwell equations the indicated group is isomorphic to Zaitsev's group of outer transformations of the electromagnetic field variables.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 45–48, August, 1977.The author is indebted to S. I. Kruglov, Yu. A. Kurochkin, and E. A. Tolkachev for a critical and stimulating discussion of the present results.  相似文献   

8.
The principal sigma model and Abelian gauge fields coupling is studied. By expressing the first-order formulation of the gauge field equations an implicit on-shell scalar-gauge field decoupling structure is revealed. It is also shown that due to this decoupling structure the scalars of the theory belong to the pure sigma model and the gauge fields sector consists of a number of coupled Maxwell theories with currents partially induced by the scalars.  相似文献   

9.
Dynamical equations describing evolution of state functions in space-time of a given metric are important components of physical theories of particles. A method based on a group of the metric is used to obtain an infinite set of general dynamical equations for a scalar and analytical function representing free and spinless particles. It is shown that this set of equations is the same for any group of the metric that consists of an invariant Abelian subgroup of translations in time and space. For Galilean space-time, such group is the extended Galilei group. Using this group, it is proved that the infinite set of equations has only one subset of Galilean invariant dynamical equations, and that the equations of this subset are Schr?dinger-like equations.  相似文献   

10.
首次讨论了非Abel对偶超导理论中的涡旋管性质。 在Cho等工作的基础上进一步研究了非Abel情况下的动力学, 并推导出了哈密顿量和运动方程。 重点讨论了限制规范势对应的非Abel对偶超导理论性质, 并给出了D型及N型两类整数涡旋的具体数值解。 通过与传统的Abel对偶超导理论的对比分析,发现两者的运动方程形式及涡旋解基本一致, 这表明利用Abel对偶超导模型研究夸克色禁闭问题是合理的。 We have discussed vortices in the non Abelian dual superconductor theory. Based on the work of Cho et al., the Hamiltonian and the equations of motion of non Abelian model were discussed in details. The non Abelian dual superconductor theory related to the restricted guage potential was underlined and solutions of D type and N type integer vortices were obtained. Comparing with the traditional Abelian dual superconductor theory, we found that the the equations of motion and solutions of vortices in two models are almost same, which indicates it is reasonable to study quark confinement based on the Abelian dual superconductor theory.  相似文献   

11.
We illustrate a metric formulation of Galilean invariance by constructing wave equations with gauge fields. It consists of expressing nonrelativistic equations in a covariant form, but with a five-dimensional Riemannian manifold. First we use the tensorial expressions of electromagnetism to obtain the two Galilean limits of electromagnetism found previously by Le Bellac and Lévy-Leblond. Then we examine the nonrelativistic version of the linear Dirac wave equation. With an Abelian gauge field we find, in a weak field approximation, the Pauli equation as well as the spin—orbit interaction and a part reminiscent of the Darwin term. We also propose a generalized model involving the interaction of the Dirac field with a non-Abelian gauge field; the SU(2) Hamiltonian is given as an example.  相似文献   

12.
In this Letter we construct Abelian extensions of the group of diffecomorphisms of a torus. We consider the Jacobian map, which is a crossed homomorphism from the group of diffeomorphisms into a toroidal gauge group. A pull-back under this map of an invariant central 2-cocycle on a gauge group turns out to be an Abelian cocycle on the group of diffeomorphisms. In the case of a circle we get an interpretation of the Virasoro–Bott cocycle as a pull-back of the Heisenberg cocycle. We also give an Abelian generalization of the Virasoro–Bott cocycle to the case of a manifold with a volume form.  相似文献   

13.
It is shown that a space-time admitting a nonsingular 2-form satisfying the source-free Maxwell equations and a Lorentzian involution under which the 2-form and the exterior derivative of a related 2-form are skew invariant while the trace-free Ricci tensor and the covariant derivative of the involution itself are invariant possesses locally an invertible 2-parameter Abelian isometry group with nonsingular orbits.On sabbatical leave from the Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada.  相似文献   

14.
Quantisation of the Abelian gauge field in some classes of the noncovariant infrared-soft gauges can be carried out consistently based on the classical field equations and the basic principles of stochastic mechanics.  相似文献   

15.
Numerical 1D-3V solutions of the Wong-Yang-Mills equations with anisotropic particle momentum distributions are presented. They confirm the existence of plasma instabilities for weak initial fields and of their saturation at a level where the particle motion is affected, similar to Abelian plasmas. The isotropization of the particle momenta by strong random fields is shown explicitly, as well as their nearly exponential distribution up to a typical hard scale, which arises from scattering off field fluctuations. By variation of the lattice spacing we show that the effects described here are independent of the UV field modes near the end of the Brioullin zone.  相似文献   

16.
The theme of doing quantum mechanics on all Abelian groups goes back to Schwinger and Weyl. This theme was studied earlier from the point of view of approximating quantum systems in infinite-dimensional spaces by those associated to finite Abelian groups. This Letter links this theme to deformation quantization, and explores the set of noncommutative associative algebra structures on the Schwartz-Weil algebra of any locally compact separable Abelian group. If the group is a vector space of even dimension over a non-Archimedean local fieldK, there exists a family of noncommutative (Moyal) structures parametrized by the local field and containing membersarbitrarily close to the classical one, although the classical algebra is rigid in the sense of deformation theory. The-products are defined by Fourier integral operators. The problem of constructing sucharithmetic Moyal structures on the algebra of Schwartz-Bruhat functions on manifolds that are locally likeK 2n is raised.In memory of Julian Schwinger  相似文献   

17.
We study the model of an Abelian vector field with Chern-Simons terms coupled to fermions in (2+1) dimensions and quantize it canonically using the Dirac-Bergmann algorithm. An equivalent theory of constructed vortex field is established in the Hamil tonian formalism in which the long-range interaction has been removed and short-range interaction is taken up the former position. These vortex fields obey the fractional statistics in general, make the long-range effect in its structure, and satisfy a set of Bogomol'nyi-type equations. We further show the exotic statistics for these configurations and establish an angular-momentum-anomaly connection.  相似文献   

18.
Starting from gravity as a Chern–Simons action for the AdS algebra in five dimensions, it is possible to modify the theory through an expansion of the Lie algebra that leads to a system consisting of the Einstein–Hilbert action plus non-minimally coupled matter. The modified system is gauge invariant under the Poincaré group enlarged by an Abelian ideal. Although the resulting action naively looks like general relativity plus corrections due to matter sources, it is shown that the non-minimal couplings produce a radical departure from GR. Indeed, the dynamics is not continuously connected to the one obtained from Einstein–Hilbert action. In a matter-free configuration and in the torsionless sector, the field equations are too strong a restriction on the geometry as the metric must satisfy both the Einstein and pure Gauss–Bonnet equations. In particular, the five-dimensional Schwarzschild geometry fails to be a solution; however, configurations corresponding to a brane-world with positive cosmological constant on the worldsheet are admissible when one of the matter fields is switched on. These results can be extended to higher odd dimensions.  相似文献   

19.
The study of generalized field associated with Abelian dyons has been undertaken and it has been demonstrated that topologically, a non-Abelian gauge theory is equivalent to a set of Abelian gauge theories supplemented by dyons which undergo condensation leading to confinement and consequently to superconducting model of QCD vacuum, where the Higgs field plays the role of a regulator only. Constructing the effective action for dyonic field in Abelian projection of QCD, it has been demonstrated that any charge (electrical or magnetic) of dyon screens its own direct potential to which it minimally couples and anti-screens the dual potential leading to dual superconductivity in accordance with generalized Meissner effect. In this Abelian projection of QCD an Abelian Higgs model (AHM) has been successfully constructed and it has been shown to incorporate dual superconductivity and confinement as the consequence of dyonic condensation. It has been demonstrated that in AHM t’ Hooft loop creates the string (AHM-string) around which the monopole current under London limit leads to vanishing coherence length in the chromo-magnetic superconductor. It has also been shown that in London limit the squared density of monopole current around AHM-string has a maximum at the distance of the order of penetration length.  相似文献   

20.
We construct a covariant functor from a category of Abelian principal bundles over globally hyperbolic spacetimes to a category of *-algebras that describes quantized principal connections. We work within an appropriate differential geometric setting by using the bundle of connections and we study the full gauge group, namely the group of vertical principal bundle automorphisms. Properties of our functor are investigated in detail and, similar to earlier works, it is found that due to topological obstructions the locality property of locally covariant quantum field theory is violated. Furthermore, we prove that, for Abelian structure groups containing a nontrivial compact factor, the gauge invariant Borchers-Uhlmann algebra of the vector dual of the bundle of connections is not separating on gauge equivalence classes of principal connections. We introduce a topological generalization of the concept of locally covariant quantum fields. As examples, we construct for the category of principal U(1)-bundles two natural transformations from singular homology functors to the quantum field theory functor that can be interpreted as the Chern class and the electric charge. In this case we also prove that the electric charges can be consistently set to zero, which yields another quantum field theory functor that satisfies all axioms of locally covariant quantum field theory.  相似文献   

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