Symmetry, Reductions and New Exact Solutions of ANNV Equation Through Lax Pair

In this paper, the direct symmetry method is extended to the Lax pair of the ANNV equation. As a result, symmetries of the Lax pair and the ANNV equation are obtained at the same time. Applying the obtained symmetry, the （2＋1）-dimensional Lax pair is reduced to （1＋1）-dimensional Lax pair, whose compatibility yields the reduction of the ANNV equation. Based on the obtained reductions of the ANNV equation, a lot of new exact solutions for the ANNV equation are found. This shows that for an integrable system, both the symmetry and the reductions can be obtained through its corresponding Lax pair.

Lax Pair and Darboux Transformation for a Variable-Coefficient Fifth-Order Korteweg-de Vries Equation with Symbolic Computation

In this paper, we put our focus on a variable-coe^cient fifth-order Korteweg-de Vries （fKdV） equation, which possesses a great number of excellent properties and is of current importance in physical and engineering fields. Certain constraints are worked out, which make sure the integrability of such an equation. Under those constraints, some integrable properties are derived, such as the Lax pair and Darboux transformation. Via the Darboux transformation, which is an exercisable way to generate solutions in a recursive manner, the one- and two-solitonic solutions are presented and the relevant physical applications of these solitonic structures in some fields are also pointed out.

A Bilinear Backlund Transformation and Lax Pair for a （1＋1）-Dimensional Differential-Difference sine-Gordon Equation

In this paper, we obtain a 1＋1 dimensional integrable differential-difference model for the sine-Gordon equation by Hirota＇s discretization method. A bilinear Backlund transformation and the associated Lax pair are also proposed/or this model.

Finite symmetry transformation group of the Konopelchenko Dubrovsky equation from its Lax pair

Starting from a weak Lax pair, the general Lie point symmetry group of the Konopelchenko-Dubrovsky equation is obtained by using the general direct method. And the corresponding Lie algebra structure is proved to be a Kac-Mood-Virasoro type. Furthermore, a new multi-soliton solution for the Konopelchenko-Dubrovsky equation is also given from this symmetry group and a known solution.

Lax Pairs for Integrable Six-Vertex Model with Color Parameters

Using the colored Yang–Baxter equation, the Lax pairs for the system with color parameters and periodic boundary conditions are derived. The explicit expressions of the Lax pairs for the six-vertex standard matrices of both the Baxter and free-Fermion types are given.

Construction of Recursion Formulas for Lax Pairs of (2+1)-Dimensional Equation: Modified Generalized Dispersive Long Wave Equation

In this article, we study the Lax pairs of -dimensional equation: the modified generalized dispersive long wave (MGDLW) equation. Based on the well-known binary Darboux transformation, we dig out the recursion formulas of the first part of the Lax pairs. Then by further discussion and doing some revisional work, we make the recursion formulas fit for the second part of Lax pairs. At last, some solutions to the MGDLW equation are worked out by using the recursion formula.

Symmetry Reductions of a Lax Pair for(2+1)-Dimensional Differential Sawada-Kotera Equation

Based on the symbolic computational system Maple, the similarity reductions of a Lax pair for the （2＋1 ）-dimensional differential Sawada Kotera （SK） equation by the classical Lie point group method, are presented. We obtain several interesting reductions. Comparing the reduced Lax pair＇s compatibility with the reduced SK equation under the same symmetry group, we find that the reduced Lax pairs do not always lead to the reduced SK equation. In general, the reduced equations are the subsets of the compatibility conditions of the reduced Lax pair.

Pseudopotentials,Lax Pairs and Bcklund Transformations for Generalized Fifth-Order KdV Equation

Based on the method developed by Nucci, the pseudopotentials, Lax pairs and the mngulanty mamtoia equations of the generalized fifth-order KdV equation are derived. By choosing different coefficient, the corresponding results and the Backlund transformations can be obtained on three conditioners which include Caudrey-Dodd-Cibbon- Sawada-Kotera equation, the Lax equation and the Kaup-kupershmidt equation.

Lax pair and vector semi-rational nonautonomous rogue waves for a coupled time-dependent coefficient fourth-order nonlinear Schrodinger system in an inhomogeneous optical fiber

Optical fibers are seen in the optical sensing and optical fiber communication. Simultaneous propagation of optical pulses in an inhomogeneous optical fiber is described by a coupled time-dependent coefficient fourth-order nonlinear Schr?dinger system, which is discussed in this paper. For such a system, we work out the Lax pair, Darboux transformation, and corresponding vector semi-rational nonautonomous rogue wave solutions. When the group velocity dispersion(GVD) and fourth-order dispersion(FOD) coefficients are the constants, we exhibit the first-and second-order vector semirational rogue waves which are composed of the four-petalled rogue waves and eye-shaped breathers. Both the width of the rogue wave along the time axis and temporal separation between the adjacent peaks of the breather decrease with the GVD coefficient or FOD coefficient. With the GVD and FOD coefficients as the linear, cosine, and exponential functions, we respectively present the first-and second-order periodic vector semi-rational rogue waves, first-and second-order asymmetry vector semi-rational rogue waves, and interactions between the eye-shaped breathers and the composite rogue waves.

Jimbo-Miwa-Like方程的Lax可积性研究

基于双Bell多项式方法,将Jimbo-Miwa-Like方程化为双线性形式,运用Bell多项式的相关性质,构造出方程的双Bell多项式B?cklund变换、双线性B?cklund变换、Lax对、无穷守恒律和孤子解。运用试探函数法和符号计算软件Mathematica获得方程的复合型解,并选取适当的参数,绘制一部分精确解的图像来说明性质。

Lax Pairs and Integrability Conditions of Higher-Order Nonlinear Schrdinger Equations

We derive the Lax pairs and integrability conditions of the nonlinear Schrdinger equation with higher-order terms, complex potentials, and time-dependent coefficients. Cubic and quintic nonlinearities together with derivative terms are considered. The Lax pairs and integrability conditions for some of the well-known nonlinear Schrdinger equations, including a new equation which was not considered previously in the literature, are then derived as special cases. We show most clearly with a similarity transformation that the higher-order terms restrict the integrability to linear potential in contrast with quadratic potential for the standard nonlinear Schrdinger equation.

GENERALIZED BOUSSINESQ EQUATION AND KdV EQUATION——PAINLEVE PROPERTIES,BACKLUND TRANSFORMATIONS AND LAX PAIRS

Starting from the similarity reductions of the Kadomtsev-Petviashvili equation, we getthe generalized Boussinesq equation and the generalized KdV equation which possess somearbitrary functions as their variable coefficients. Using the singularity analysis methoddeveloped by J. Weiss and M. D. Kruskal et al. we have proved the sufficient conditionsof the integrabilities and Painleve properties of these two equations. Their Backlund trans-formations and the singularity manifold equations (generalized Schwartz-Boussinesq equationand Schwartz-KdV equation) are obtained. And then these two equations are linearized, i. e.their Lax pairs are given with the time-independent arbitrary spectral parameters includedexplicitly.

An Eight Component Integrable Hamiltonian Hierarchy from a Reduced Seventh-Order Matrix Spectral Problem

We present an eight component integrable Hamiltonian hierarchy, based on a reduced seventh order matrix spectral problem, with the aim of aiding the study and classification of multicomponent integrable models and their underlying mathematical structures. The zero-curvature formulation is the tool to construct a recursion operator from the spatial matrix problem. The second and third set of integrable equations present integrable nonlinear Schrödinger and modified Korteweg-de Vries type equations, respectively. The trace identity is used to construct Hamiltonian structures, and the first three Hamiltonian functionals so generated are computed.

α-螺旋蛋白中三分量高阶非线性薛定谔方程的怪波解

以三分量高阶非线性薛定谔方程为α-螺旋蛋白中生物能量沿蛋白质分子链传输的控制方程,研究三个相互耦合的波函数在极限状态下激发的怪波.基于控制模型的Lax对表示,利用规范变换得到了达布变换的行列式形式.通过Lax对的变量分离和平移参数的引入,给出了怪波激发的代数条件.进一步利用幂级数的多项分裂构造怪波解的基础特征函数,并由此导出退化的达布变换.最后通过退化的达布变换获得怪波解,并在不同参数下,用三维图形示例怪波的波形演化及其极值轨迹.

Lax对变换与约束流的Lax表示

首先做一个恰当的 Lax对变换 ,使变换前后的 Lax对保持孤子方程族不变 .利用文献提供的方法 ,求出 TD方程族约束流的 Lax表示及在某约束条件下对称约束流的

五阶耦合扩展mKdV方程的N阶孤子解

基于二分量五阶耦合扩展修正的Korteweg-de Vries(mKdV)方程,借助广义Darboux变换和Taylor展式,得到方程N阶孤子解的迭代表达式.对谱参数的实部和虚部分类讨论,取合适的自由参数,通过数值模拟展示孤子间的相互作用图,进一步分析不同参数对孤子间弹性及非弹性碰撞的影响.所得结果对高阶孤子的研究具有一定的理论意义.

Finite Symmetry Transformation Groups and Exact Solutions of Lax Integrable Systems

The general Lie point symmetry groups of the Nizhnik-Novikov-Vesselov (NNV) equation and the asymmetric NNV equation are given by a simple direct method with help of their weak Lax pairs.

变系数5阶Korteweg-de Vries方程的Lax对和自-Bcklund变换研究

文中以在众多领域中存在广泛应用的变系数函数5阶Korteweg-de Vries方程为研究对象,首先基于Ablowitz-Kaup-Newell-Segur系统推出方程存在孤子解的约束条件和Lax对,进而构造方程的自-Bcklund变换和孤子解,并分析讨论变系数函数对孤子解传播特征的影响.

广义Hamilton方程族的Lax对的变换及其在非线性化方法中的应用

给出了广义Ｈａｍｉｌｔｏｎ方程族的Ｌａｘ对的变换方法，指出了这种Ｌａｘ对的变换在非线性化方法中的应用。

扩展的Boussinesq系统Lax对的Bcklund变换和递推求解公式的导出

本文研究2+1维的扩展经典Boussinesq系统。首先,研究了系统的Lax对,找出了一个形式十分新颖的带有一个任意函数的Bcklund变换。然后,又导出了Lax对的特征函数的生成公式。最后,利用Bcklund变换和Lax对特征函数生成公式相结合得出了Lax对的递推求解公式。利用此递推公式,求出了一些Lax对的解。