广义耦合KdV孤子方程的达布变换及其偶孤子解

根据广义耦合KdV孤子方程的Lax对, 借助谱问题的规范变换, 一个包含多参数的达布变换被构造出来. 利用达布变换来产生广义耦合KdV孤子方程的偶孤子解, 并且用行列式的形式来表达广义耦合KdV孤子方程的偶孤子解. 作为应用, 广义耦合KdV孤子方程的偶孤子解的前两个例子被给出.     

广义耦合KdV孤子方程的达布变换及其奇孤子解

借助谱问题的规范变换, 给出广义耦合KdV孤子方程的达布变换,利用达布变换来产生广义耦合KdV孤子方程的奇孤子解,并且用行列式的形式来表达广义耦合KdV孤子方程的奇孤子解．作为应用,广义耦合KdV孤子方程奇孤子解的前两个例子被给出．     

散焦mKdV方程的N重暗孤子解的行列式表示

该文首先构造了耦合的mKdV方程的新的达布变换,同时显式给出了它的达布矩阵T_N和新解q~([N]),r~([N])的行列式表示.其次,考虑将约化条件r=q*附加到该达布变换上,以及考虑一个周期的非零种子解,得到了散焦mKdV方程的N重暗孤子解的行列式表示.最后,证明了暗的单孤子解和暗的2孤子解是光滑的,进一步证明了暗的N(N≥2)孤子解至少在某一邻域内是光滑的.     

四耦合非线性薛定谔方程的矢量孤子解及叠加解

本文通过两种方法分别得到四耦合非线性薛定谔方程的矢量孤子解及一阶叠加解.第一种方法是利用发展的广田双线性方法,得到四耦合非线性薛定谔方程的单、双孤子解,以及一种具有呼吸行为的新解.第二种方法是利用一阶达布变换,得到一阶怪波解以及怪波与孤子、呼吸子相互作用的一阶叠加解.     

一类非线性偏微分方程组的直接解法

根据Hopf-Cole变换法和试探函数法的基本思想,引入一个变换,并把它应用于求解(2+1)维破裂孤子方程组、(2+1)维Nizhnik-Novikov-Vesslov方程组和(2+1)维Broer-Kaup方程组,得到了这三个方程组的许多新的解析解,包括孤波解和奇异行波解.该方法也适用于其它方程组.     

耦合KdV方程的几个精确解

Darboux变换是求孤子方程的精确解的一种新方法。它借助于孤子方程的Lax对。从方程的平凡解导出新的非平凡解。本文对一个四阶特征值问题找出了Darboux变换,并由此得到耦合KdV方程的孤子解,周期解,极点解等。     

用Hirota双线性方法构造一种(3+1)维高维孤子方程的多孤子解

通过两种方法构造了一种(3+1)维高维孤子方程的孤子解.第一种方法是利用对数函数变换,将其化成双线性形式的方程,在用级数扰动法求解双线性方程的单孤子解、双孤子解和N-孤子解.第二种方法是用广义有理多项式与试探法相结合,构造了(3+1)维高维孤子方程的怪波解.     

高阶(2+1)维Broer-Kaup方程的局域相干结构

利用推广的齐次平衡方法,研究高阶(2+1)维Broer-Kaup方程的局域相干结构.首先基于推广的齐次平衡方法,给出这个模型的一个非线性变换,并把它变换成一个线性化的方程.然后从线性化方程出发,构造出一个分离变量的拟解.由于拟解中不仅含有两个y的任意函数,而且还有{αi,βi,γk,kj,lk}和{N,M,L}这些参数可以任意选取,因此合适的选择这些函数和参数,可以得到新的相当丰富的孤子结构.方法直接而简单,可推广应用一大类(2+1)维非线性物理模.     

掺铒光纤中一类多耦合Hirota-SIT系统的孤子和呼吸子解

考虑一类多耦合Hirota Self-Induced Transparency系统,首先运用AKNS方法构造系统的Lax对,并推导出相应的达布变换公式.其次在初始零解的背景下求得了单孤子解和双孤子解,在平面波背景下讨论了单呼吸子解和双呼吸子解.最后在软件Mathematica的帮助下,通过图像来分析这些解的动态特征.     

一个2+1维变形Boussinesq方程的N孤子解

研究了一个2＋1维变形Boussinesq非线性发展方程：utt-uxx-uyy-3（u^2）xx-uxxxx=0,运用Hirota双线性方法得到它的N孤子解.     

Explicit solution and Darboux transformation for a new discrete integrable soliton hierarchy with 4×4 Lax pairs

The Darboux transformation method with 4×4 spectral problem has more complexity than 2×2 and 3×3 spectral problems. In this paper, we start from a new discrete spectral problem with a 4×4 Lax pairs and construct a lattice hierarchy by properly choosing an auxiliary spectral problem, which can be reduced to a new discrete soliton hierarchy. For the obtained lattice integrable coupling equation, we establish a Darboux transformation and apply the gauge transformation to a specific equation and then the explicit solutions of the lattice integrable coupling equation are obtained. Copyright © 2017 John Wiley & Sons, Ltd.     

Darboux transformation and explicit solutions for two integrable equations

A new N-fold Darboux transformation for two integrable equations is constructed with the help of a gauge transformation for the spectral problem proposed by Qiao [Z.J. Qiao, Phys. Lett. A 192 (1994) 316-322]. By the Darboux transformation, explicit soliton and multi-soliton solutions for the two equations are obtained. In particular, soliton and complexiton solutions are shown through some figures.     

The Darboux transformation associated with two-parameter lattice soliton equation

A new discrete matrix spectral problem with two arbitrary constants is introduced. The corresponding two-parameter integrable lattice soliton equation is obtained through the discrete zero curvature representation, and the resulting integrable lattice equation reduce to the Toda lattice in rational form for a special choice of the parameters. A Darboux transformation (DT) for the lattice soliton equation is constructed. As an application, an explicit solution of the two-parameter lattice soliton equation is presented.     

矩阵AKNS系列Darboux变换的行列式表示

本文将建立矩阵AKNS系列Darboux变换的行列式表示。为此,推广了Sylvester恒等式,并利用它化简Darboux迭带所致的行列式 最后,给出了几个著名的矩阵孤立子方程,如矩阵KdV、矩阵NLS、矩阵MKdV等的孤立子解。     

Dark and antidark solitons for the defocusing coupled Sasa–Satsuma system by the Darboux transformation

In this article, we construct the $N$-fold Darboux transformation for the defocusing coupled Sasa–Satsuma system which describes the simultaneous propagation of two nonlinear waves in optical fibers with higher order effects. With the non-zero constant background as a seed, we derive the dark and antidark soliton solutions from the once-iterated formula. We find that this coupled system can exhibit the dark–dark, dark–antidark and antidark–dark vector solitons.     

Envelope soliton resonances and broer-kaup-type non-madelung fluids

We derive an extended nonlinear dispersion for envelope soliton equations and also find generalized equations of the nonlinear Schr?dinger (NLS) type associated with this dispersion. We show that space dilatations imply hyperbolic rotation of the pair of dual equations, the NLS and resonant NLS (RNLS) equations. For the RNLS equation, in addition to the Madelung fluid representation, we find an alternative non-Madelung fluid system in the form of a Broer-Kaup system. Using the bilinear form for the RNLS equation, we construct the soliton resonances for the Broer-Kaup system and find the corresponding integrals of motion and existence conditions for the soliton resonance and also a geometric interpretation in terms of a pseudo-Riemannian surface of constant curvature. This approach can be extended to construct a resonance version and the corresponding Broer-Kaup-type representation for any envelope soliton equation. As an example, we derive a new modified Broer-Kaup system from the modified NLS equation.     

Solving soliton equations with self-consistent sources by method of variation of parameters

Starting from the solutions of soliton equations and corresponding eigenfunctions obtained by Darboux transformation, we present a new method to solve soliton equations with self-consistent sources (SESCS) based on method of variation of parameters. The KdV equation with self-consistent sources (KdVSCS) is used as a model to illustrate this new method. In addition, we apply this method to construct some new solutions of the derivative nonlinear Schrödinger equation with self-consistent sources (DNLSSCS) such as phase solution, dark soliton solution, bright soliton solution and breather-type solution.     

DARBOUX TRANSFORMATION OF A NONLINEAR EVOLUTION EQUATION AND ITS EXPLICIT SOLUTIONS

In this paper, we study a differential-difference equation associated with discrete 3 × 3 matrix spectral problem. Based on gauge transformation of the spectral problm, Darboux transformation of the differential-difference equation is given. In order to solve the differential-difference equation, a systematic algebraic algorithm is given. As an application, explicit soliton solutions of the differential-difference equation are given.