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1.
Based on the solution of the Bargmann-Wigner equation for an arbitrary integral spin,a direct derivation of the projection operator and propagator for an arbitrayr integral spin is presented.The explicit form for the spin projection operators constructed by Behrends and Fronsdal is confirmed.The commutation rules and a general expression for the Feynman Propagator for a free particle of arbitrary integral spin are deduced. 相似文献
2.
HEYuanan HEZuoyong 《声学学报:英文版》2003,22(1):11-21
Reconstruction of the surface acoustic field of axisymmetric body with arbitrary boundary conditions using near-field acoustic data is studied.The method of numerical reconstruction based on orthonormalization function expansion(OFE) and boundary element integral(BEI) is presented which can overcome the singular integral problem in the boundary integral equations.By numerical examples,the precision of reconstruction for the non-conformal surface with the axisymmetric or non-axisymmetric vibrating on axisymmetric body is given.The results of the numerical simulation are shown that this kind of reconstruction method is available for engineering. 相似文献
3.
The shock is described by the Navier-Stokes equations of the electron and ion fluids, and coupled with Poisson‘s equation for the self-induced electric field. Profiles of the flow and electric variables in the weak or moderate shock front with or without current for different Debye lengths are presented. Comparison of profiles of flow and electric variables in the front for different heat flow modes is given. 相似文献
4.
JUGuo-Xing ZhaoXian-Lin 《理论物理通讯》2002,37(4):397-404
The solution transformations and properties of the R-matrices for two-component systems under these transformations are analyzed in details.Not all transformed R-matrices can be put into the Skalyanin‘s formalism.For those R-matrices with all required properties,the effects of solution transformations to the six-and eight-vertex systems with open boundary conditions are discussed.these effects can be one of the following types:the Hamiltonian is invariant or transposition-invariant or made in a similarity transformation,or its coupling coefficients are multiplied by an overall factor,or the spin of the system is rotated around the z axis or/and reflected with respect to some plane.In these cases,the transformed systems remain to be integrable. 相似文献
5.
We propose a general method to prove the uniqueness of the inversion problems described by first-kind integral equations.The method depends on the analytical properties of the Fourier transform of the integral kernel and the finiteness of the total states (or probability,if normalized),the integration of the “local” density of states,which is a rather moderate condition and satisfied by many inversion problems arising from physics and engineering. 相似文献
6.
Evolution of Spin and Charge in a System with Interacting Impurity and Conducting Electrons *
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We investigate the dynamics of spin and charge in an interacting system consisting of impurity and conduct-ing electrons. The time evolution of spin and charge in the impurity is given by solving the time-dependent Schroedinger equations for the many-body states of the interacting system. By switching on the interaction be-tween impurity and conducting electrons, the spin and charge of the impurity begin oscillations with frequencies that reflect the elementary excitations of the interacting system. The dynamics reflects the basic picture of the Kondo effect. 相似文献
7.
Based on the solution to Bargmann-Wigner equation for a particle with arbitrary half-integral spin, a direct derivation of the projection operator and propagator for a particle with arbitrary half-integral spin is worked out. The projection operator constructed by Behrends and Fronsdal is re-deduced and confirmed and simplified, the general commutation rules and Feynman propagator with additional non-covariant terms for a free particle with arbitrary half-integral spin are derived, and explicit expressions for the propagators for spins 3/2, 5/2 and 7/2 are provided. 相似文献
8.
Comparison of calculation methods for the tunnel splitting at excited states of biaxial spin models
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We present the calculation and comparison of tunnel splitting at excited levels of biaxial spin models by various methods, including the generalized instanton method, the generalized path integral method for coherent spin states, the perturbation method, and the exact method by numerical diagonalization of the Hamiltonian. It is found that, for integer spin with spin number around 10, tunnel splitting predicted by the generalized path integral for coherent spin states is about 10^{-n} times of the exact numerical result for the nth excited level, while the ratio of the results of the perturbation method and the exact numerical method diverges in the large spin limit. We thus conclude that the generalized instanton method is the best approximate way for calculating tunnel splitting in spin models. 相似文献
9.
The algebraic structure and Poisson's integral theory of mechanico-electrical
systems are studied. The Hamilton canonical equations and generalized Hamilton
canonical equations and their the contravariant algebraic forms for
mechanico-electrical systems are obtained. The Lie algebraic structure and the
Poisson's integral theory of Lagrange mechanico-electrical systems are derived. The
Lie algebraic structure admitted and Poisson's integral theory of the
Lagrange--Maxwell mechanico-electrical systems are presented. Two examples are
presented to illustrate these results. 相似文献
10.
The generalized Bethe-ansatz method of thermodynamic analysis of integrable systems was employed to compute the free energy of a classical integrable model,i.e.the Landau-Lifshitz model.Using the action-angle variables of the model and by imposing a periodic boundary condition.we derive a phase-shifted density of states for the excitations of the system.The free energy,in the thermodynamic limit,can be expressed analytic in terms of two coupled nonlinear integral equations of the finie temperature excited energy for effective phonons and kinks (antikinks).we solve these equations iteratively for a special case that the model is in the limit of anisotropic strong yz coupling. 相似文献
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12.
从高自旋态的Bargmann-Wigner方程出发,建立了整数自旋粒子的运动方程,通过求解方程得到了一套整数自旋粒子波函数,并建立了等效Largrange形式. 相似文献
13.
On the Boundary Integral Equations for a Two-Dimensional Slowly Rotating Highly Viscous Fluid Flow
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D. Lesnic 《advances in applied mathematics and mechanics.》2009,1(1):140-150
In this paper, the two-dimensional slowly rotating highly viscous
fluid flow in small cavities is modelled by the triharmonic equation
for the streamfunction. The Dirichlet problem for this triharmonic
equation is recast as a set of three boundary integral equations
which however, do not have a unique solution for three exceptional
geometries of the boundary curve surrounding the planar solution
domain. This defect can be removed either by using modified
fundamental solutions or by adding two supplementary boundary
integral conditions which the solution of the boundary integral
equations must satisfy. The analysis is further generalized to
polyharmonic equations. 相似文献
14.
I. V. Shirokov 《Russian Physics Journal》1992,35(6):524-529
Relativistic Poincaré-invariant wave equations for zero-mass and heavy particles with an arbitrary spin are constructed on the basis of special infinite-dimensional representation of the Lorentz group. The equations form a compatible system of linear differential equations for an unknown scalar function and contain spin s as a parameter (arbitrary complex number). It is also shown that the equations obtained in this way include the well-known finite-component wave equations as a special case of half-integral or integral spin.State University, Omsk. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 39–44, June, 1992. 相似文献
15.
A. T. Grecu D. Grecu Anca Visinescu 《International Journal of Theoretical Physics》2007,46(5):1190-1204
The modulational instability (MI) in the class of NLS equations is discussed using a statistical approach (SAMI). A kinetic
equation for the two-point correlation function is studied in a linear approximation, and an integral stability equation is
found. The modulational instability is associated with a positive imaginary part of the frequency. The integral equation is
solved for different types of initial distributions (δ-function, Lorentzian) and the results are compared with those obtained
using a deterministic approach (DAMI). The differences between MI of the normal NLS equation and derivative NLS equations
is emphasized.
PACS: 05.45. 相似文献
16.
Zekeriya Altaç 《Journal of Quantitative Spectroscopy & Radiative Transfer》2003,77(2):177-192
Radiative integral transfer equations for one-dimensional solid cylinder with absorbing, emitting and linearly anisotropic-scattering inhomogeneous medium were derived by Abulwafa et al. (JQSRT 62 (1999) 755). The anisotropic terms in the integral equations and their results for anisotropic benchmark problems (JQSRT 66 (2000) 487) are inaccurate. In this study, the integral equations for absorbing, emitting and linearly anisotropic-scattering medium are rederived, and the integral equations for one-dimensional solid cylindrical medium are solved. The results are compared with selected cases using the discrete ordinates S16 and the exact solutions available in the literature. 相似文献
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18.
Starting from Einstein's equations of the Classical General Relativity, new kinds of solutions for the Mixmaster model are explored. By dispensing with the extension to the complex variable field, which is usual in problems such as the Laplace equation or the harmonic oscillator, in a similar manner to that of Quantum Mechanics, the equations appear to have solutions that belong to the complex General Relativity. A first integral is performed by establishing a separation of the first derivatives. Then a second integral is obtained once the respective equations with separate variables are found and whose integrals provide a family of complex solutions. However, reality conditions do not seem to be easily imposed at this stage. Above all, it is significant that the classical Einstein's equations for the debatably integrable Mixmaster model present complex solutions. 相似文献
19.
Laurence I. Gould 《International Journal of Theoretical Physics》1989,28(3):335-364
A formalism is developed whereby balance laws are directly obtained from nonlocal (integrodifferential) linear second-order equations of motion for systems described by several dependent variables. These laws augment the equations of motion as further useful information about the physical system and, under certain conditions, are shown to reduce to conservation laws. The formalism can be applied to physical systems whose equations of motion may be relativistic and either classical or quantum. It is shown to facilitate obtaining global conservation laws for quantities which include energy and momentum. Applications of the formalism are given for a nonlocal Schrödinger equation and for a system of local relativistic equations of motion describing particles of arbitrary integral spin. 相似文献