共查询到20条相似文献,搜索用时 187 毫秒
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The renormalization properties of the self-interacting complex scalar field are discussed, its Dyson equation is the presented,the B-S equation of the identical- bosons and relation between the irreducible kernel and the vertex function are derived. 相似文献
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系统地讨论了含修正项的KdV方程的直接微扰方法.从反散射变换所得的不含修正项方程的严格多孤子解出发,导出了线性化算子的零本征值的所有本征函数——平方Jost函数.引入了它们所对应的伴随函数和定义了内积.计算了应有的正交关系,并自然得到单位元的平方Jost函数的展开式.利用广义的Marchenko方程,证明了平方Jost函数的完备性.同时得到展开式中的积分是沿实轴从-∞到∞,但在原点附近将从上方绕过.这不同于过去所得的Cauchy主值积分.为最明确显示这一差别,在单孤子情况下又用平方Jost函数的显式,直接作了验证.同时指出,以前由于取Cauchy主值积分导出的KdV方程所特有的孤子尾,在采用从上方绕过原点的积分时,则事实上并不存在.
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从速度v的傅里叶空间K的动力学方程出发,采用算子运算及变换方法,可较简便的算出静电湍流场中的重整化色散方程,在以有效关联时间代替湍流场的时、空关联的近似下,计算了有限关联时间效应的作用,表明它是削弱湍流场影响的。短关联时间极限可看成是湍流场影响的上限估计。讨论了湍流场对离声波、电子朗缪波和低频漂移波的影响。
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C. Beck 《Optics & Laser Technology》1977,9(2):81-85
A theory of random small-angle scattering is presented. The photon dispersion partial differential equation is derived and the dispersion coefficient characterizing the medium is introduced. The equation is solved for a spatial impulse. The modulation transfer function and the contrast loss are derived as a funcion of spatial frequency, dispersion coefficient, and object-to-image distance. The limitation on resolution is shown by an indeterminancy relation based on the dispersion coefficient. The dispersion angle (rms value of scattering angle) is calculated as an example. 相似文献
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本文运用量级分析和渐进展开匹配方法推导了适用于旋转系统流动分离的渐进结构方程,此方程具有三层结构的特点,每层有不同的流动性质,层与层之间通过匹配关系联系起来,旋转效应在渐进结构中不出现。由于层间参数的传递反映了该方程及其定解条件的椭圆型特征,加之三层区域的精细结构,该方程为激波/边界层干扰的计算提供了手段。 相似文献
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A. A. Veldhorst L. Bøhling J. C. Dyre T. B. Schrøder 《The European Physical Journal B - Condensed Matter and Complex Systems》2012,85(1):21
Zeroth-order complex dispersion equation of a cylindrical metallic nanowire has been
solved analytically to get dispersion relations of surface plasmon-polaritons (SPPs) by
approximate methods. The back bending of the dispersion relation can be well described by
the analytical solutions, confirming that the back bending is originated from the metal
Ohmic loss. Basing on the analytical solutions, the back bending point of the dispersion
relation used for the measurement of the metallic Ohmic loss has also been suggested. 相似文献
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A new approximate analytical approach for dispersion relation of the nonlinear Klein-Gordon equation
A novel approach is presented for obtaining approximate analytical expressions for the dispersion relation of periodic wavetrains in the nonlinear Klein-Gordon equation with even potential function. By coupling linearization of the governing equation with the method of harmonic balance, we establish two general analytical approximate formulas for the dispersion relation, which depends on the amplitude of the periodic wavetrain. These formulas are valid for small as well as large amplitude of the wavetrain. They are also applicable to the large amplitude regime, which the conventional perturbation method fails to provide any solution, of the nonlinear system under study. Three examples are demonstrated to illustrate the excellent approximate solutions of the proposed formulas with respect to the exact solutions of the dispersion relation. (c) 2001 American Institute of Physics. 相似文献
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《Journal of Nonlinear Mathematical Physics》2013,20(4):591-603
It is shown that the celebrated Menelaus relation, Hirota–Miwa bilinear equation for KP hierarchy and Fay's trisecant formula similar to the WDVV equation are associativity conditions for structure constants of certain three-dimensional quasi-algebra. 相似文献
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研究了强耦合尘埃等离子体的尘埃声波的线性色散关系和尘埃声孤波的非线性传播。考虑一个包含电子、离子、正电扰动尘埃颗粒的完全电离的三成分模型等离子体。假定其电子、离子数密度服从玻尔兹曼分布,而大质量的尘埃成分用一组经典流体方程描述,对系统方程进行线性化,得到了尘埃声波的线性色散关系,发现离子的集中参数对色散关系的影响很大。用约化摄动法对系统方程进行展开,得到了描述小振幅孤波的伯格斯方程。基于伯格斯方程研究了尘埃声孤波的基本特性,发现尘埃颗粒的强耦合效应对尘埃声孤波有很大的修正作用。该研究结果有助于理解尘埃空间等离子体中局域波的一些特性。 相似文献
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研究了强耦合尘埃等离子体的尘埃声波的线性色散关系和尘埃声孤波的非线性传播。考虑一个包含电子、离子、正电扰动尘埃颗粒的完全电离的三成分模型等离子体。假定其电子、离子数密度服从玻尔兹曼分布,而大质量的尘埃成分用一组经典流体方程描述,对系统方程进行线性化,得到了尘埃声波的线性色散关系,发现离子的集中参数对色散关系的影响很大。用约化摄动法对系统方程进行展开,得到了描述小振幅孤波的伯格斯方程。基于伯格斯方程研究了尘埃声孤波的基本特性,发现尘埃颗粒的强耦合效应对尘埃声孤波有很大的修正作用。该研究结果有助于理解尘埃空间等离子体中局域波的一些特性。 相似文献
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The Hamiltonian of a radial equation is defined on a half-line,and there is a close relation between its hermitian and the boundary condition of the wave functions at the origin.If the wave functions are nonvanishing and convergent at the origin,the Hamiltonian has a one-parameter family of self-adjoint extensions which are related with the vanishness of the radial probability current at the origin.In this paper the problem on the hermitian of the Hamiltonian of a radial equation is studied systematically.Some methods for determining the parameter for the fermion moving in the magnetic monopole field are discussed. 相似文献
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Garate E.P. Fisher A. Main W.G. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1990,18(5):831-836
The linearized Lorentz force, continuity equation, and Maxwell's equations are used to calculate the system dispersion relation for a coaxial configuration of the dielectric Cherenkov maser. The system consists of two coaxial conductors lined with dielectric and an annular relativistic electron beam, which propagates between the two liners. The dispersion relation for the beam and dielectric-lined coaxial waveguide structure and the no-beam system that describes the dependence of the generated frequency on the coaxial waveguide parameters are presented. Using the linearized dispersion relation, the growth rate for the beam-TM0n waveguide mode instability is calculated in the strong-coupling tenuous beam limit 相似文献
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Unveiling the Link Between Fractional Schrödinger Equation and Light Propagation in Honeycomb Lattice
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Da Zhang Yiqi Zhang Zhaoyang Zhang Noor Ahmed Yanpeng Zhang Fuli Li Milivoj R. Belić Min Xiao 《Annalen der Physik》2017,529(9)
We suggest a real physical system — the honeycomb lattice — as a possible realization of the fractional Schrödinger equation (FSE) system, through utilization of the Dirac‐Weyl equation (DWE). The fractional Laplacian in FSE causes modulation of the dispersion relation of the system, which becomes linear in the limiting case. In the honeycomb lattice, the dispersion relation is already linear around the Dirac point, suggesting a possible connection with the FSE, since both models can be reduced to the one described by the DWE. Thus, we propagate Gaussian beams in three ways: according to FSE, honeycomb lattice around the Dirac point, and DWE, to discover universal behavior — the conical diffraction. However, if an additional potential is brought into the system, the similarity in behavior is broken, because the added potential serves as a perturbation that breaks the translational periodicity of honeycomb lattice and destroys Dirac cones in the dispersion relation. 相似文献
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采用扩散模型研究核裂变,需要求解Fokker-Planck方程。本文提出一个数值计算方法-平均隐式差分方法。对具有粘滞性的核体系的有关裂变动力学量,如几率分布、裂变率、断点处的平均动能以及鞍点到断点的平均扩散时间等一系列物理量做了计算,并与适合大粘滞性的Kramers的解析解做了比较。通过与解析解的比较及对归一常数的检验,证明计算结果精确可靠。 相似文献
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运用并矢法求解广义Helmholtz方程,结合Fourier变换、留数定理等数学处理,给出方程的并矢Green函数解析表达式;并进一步就旋波介质给出其中色散关系的另外一种求解方法. 相似文献