288 research outputs found
The partition function versus boundary conditions and confinement in the Yang-Mills theory
We analyse dependence of the partition function on the boundary condition for
the longitudinal component of the electric field strength in gauge field
theories. In a physical gauge the Gauss law constraint may be resolved
explicitly expressing this component via an integral of the physical
transversal variables. In particular, we study quantum electrodynamics with an
external charge and SU(2) gluodynamics. We find that only a charge distribution
slowly decreasing at spatial infinity can produce a nontrivial dependence in
the Abelian theory. However, in gluodynamics for temperatures below some
critical value the partition function acquires a delta-function like dependence
on the boundary condition, which leads to colour confinement.Comment: 14 pages, RevTeX, submitted to Phys. Rev.
The influence of an external magnetic field on the dynamic stress of an elastic conducting one-sided layer with a longitudinal shear crack
We study the interaction of a magnetoelastic shear wave with a curvilinear tunnel crack in an ideally conducting diamagnetic (resp. paramagnetic) one-sided (resp. two-sided) layer in the presence of an external static magnetic field. The bases of the one-sided layer are free of mechanical load, and the rim of the face is clamped or free. The corresponding linearized boundary-value problem of magnetoelasticity is reduced to a singular integrodifferential equation with subsequent implementation on a computer. We give numerical results that characterize the influence of the size of the preliminary magnetic field, the frequencies of the load, the curvature, and the orientation of the crack on the stress intensity factor.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2163
Comparative study of semiclassical approaches to quantum dynamics
Quantum states can be described equivalently by density matrices, Wigner
functions or quantum tomograms. We analyze the accuracy and performance of
three related semiclassical approaches to quantum dynamics, in particular with
respect to their numerical implementation. As test cases, we consider the time
evolution of Gaussian wave packets in different one-dimensional geometries,
whereby tunneling, resonance and anharmonicity effects are taken into account.
The results and methods are benchmarked against an exact quantum mechanical
treatment of the system, which is based on a highly efficient Chebyshev
expansion technique of the time evolution operator.Comment: 32 pages, 8 figures, corrected typos and added references; version as
publishe
The interaction of a magnetoelastic shear wave with longitudinal cavities in a conducting layer
We study the influence of a strong magnetic field on the interaction of a shear wave with longitudinal cylindrical cavities in an elastic ideally conducting layer. The resulting singular integral equation of the boundary-value problem under consideration is implemented numerically for the case of a single cavity. We present the results of computation of the stresses on the edge of a circular cavity and an elliptical cavity.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2163
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