Long-Time Asymptotics of Complex mKdV Equation with Weighted Sobolev Initial Data

In this paper, we apply $\bar{\partial}$-steepest descent method to analyze the long-time asymptotics of complex mKdV equation with the initial value belonging to weighted Sobolev spaces. Firstly, the Cauchy problem of the complex mKdV equation is transformed into the corresponding Riemann-Hilbert problem on the basis of the Lax pair and the scattering data. Then the long-time asymptotics of complex mKdV equation is obtained by studying the solution of the Riemann-Hilbert problem.     

The Initial-Boundary-Value Problems for the Hirota Equation on the Half-Line

An initial boundary-value problem for the Hirota equation on the half-line,0x∞, t0, is analysed by expressing the solution q(x, t) in terms of the solution of a matrix Riemann-Hilbert(RH) problem in the complex k-plane. This RH problem has explicit(x, t) dependence and it involves certain functions of k referred to as the spectral functions. Some of these functions are defined in terms of the initial condition q(x,0) = q_0(x), while the remaining spectral functions are defined in terms of the boundary values q(0, t) = g_0(t), q_x(0, t) = g_1(t) and q_(xx)(0, t) = g_2(t). The spectral functions satisfy an algebraic global relation which characterizes, say, g_2(t) in terms of {q_0(x), g_0(t), g_1(t)}.The spectral functions are not independent, but related by a compatibility condition, the so-called global relation.     

驻定Harry—Dym方程解的参数表示

本文推导出相联于ＨＤ（Ｈａｒｒｙ－Ｄｙｍ）族的Ｌｅｎａｒｄ递归方程的多项式解，并证明了任一驻定ＨＤ方程的解都可由非线性比的ＨＤ特征值问题的解表示。     

Cauchy-Riemann方程的Riemann-Hilbert边值问题

本文考虑多柱域上非齐次的Cauchy-Riemann方程的Riemann-Hilbert边值问题.讨论了上述边值问题可解的充分必要条件,并给出了边值问题解的积分表达式.     

The Generalized Riemann-Hilbert problem For a Multi-connected Region of Second Order Non-linear Elliptic Equations

In this paper, we consider the generalized Riemann-Hilbert problem for second order non-linear elliptic complex equation $\frac{\partial ^2 w}{\partial \bar z ^2}=F(z,w,\frac{\partial w}{\partial \bar z},\frac{\partial w}{\partial z},\frac{\partial ^2 w}{\partial z \partial \bar z}),z\in G$(1) with the boundary condition $Re[z^-n_1e^-\pii\alpha_1(z)w]=r_1(z),Re[z^-n_2e^\pi i \alpha_2(z) \frac{\partial w}{\partial \bar z}]=r_2(z),z\in \Gamma$ where $\Gamma=\Gamma_0+\Gamma_1+\cdots+\Gamma_m$ is the smooth boundary of a multi-connected region G,$n_i(i=1,2)$ are called the indices of the boundary value problem. we also obtain the following existence theorem of generalized solution. Theorem, suppose that the indices $n_i>m-1$, the coefficients of the complex equation (1) and the boundary condition (2) satisftes the condition (c),and q^0 is sufficiently small, then the seneralized Riemann-Hilbert problem.(1), (2)is solvable and the solution has theexpression (7).     

高阶Chen-Lee-Liu方程在半直线上的初边值问题

该文运用Fokas方法分析了高阶Chen-Lee-Liu方程在半直线上的初边值问题,证明了高阶Chen-Lee-Liu方程初边值问题的解可以用复λ平面上的矩阵Riemann-Hilbert问题的形式解唯一表示.     

Riemann-Hilbert approach to TD equation with nonzero boundary condition

We extend the Riemann-Hilbert approach to the TD equation, which is a highly nonlinear differential integrable equation. Zero boundary condition at infinity for the TD equation is not suitable. Inverse scattering transform for this equation involves the singular Riemann-Hilbert problem, which means that the sectionally analytic functions have singularities on the boundary curve. Regularization procedures of the singular Riemann-Hilbert problem for two cases, the general case and the case for reflectionless potentials, are considered. Solitonic solutions to the TD equation are given.     

Initial boundary value problems for the nonlinear Schrödinger equation

A new spectral method for solving initial boundary value problems for linear and integrable nonlinear partial differential equations in two independent variables is applied to the nonlinear Schrödinger equation and to its linearized version in the domain {x≥l(t), t≥0}. We show that there exist two cases: (a) if l″(t)<0, then the solution of the linear or nonlinear equations can be obtained by solving the respective scalar or matrix Riemann-Hilbert problem, which is defined on a time-dependent contour; (b) if l″(t)>0, then the Riemann-Hilbert problem is replaced by a respective scalar or matrix $\bar \partial $ problem on a time-independent domain. In both cases, the solution is expressed in a spectrally decomposed form.     

The Riemann-Hilbert problem for certain poly domains and its connection to the Riemann problem

The Riemann-Hilbert problem is studied for holomorphic functions in higher dimensional poly domains and the explicit constructive solution is given. The connection between the Riemann problem and the Riemann-Hilbert problem for poly domains is presented and proven. Contrary to earlier studies, our results provide explicit solutions and are not attached to any artificial assumptions.     

N-SOLITON SOLUTION OF THE KUNDU-TYPE EQUATION VIA RIEMANN-HILBERT APPROACH

In this article, we focus on investigating the Kundu-type equation with zero boundary condition at infinity. Based on the analytical and symmetric properties of eigenfunctions and spectral matrix of its Lax pair, a Riemann-Hilbert problem for the initial value problem of the Kundu-type equation is constructed. Further through solving the regular and nonregular Riemann-Hilbert problem, a kind of general N-soliton solution of the Kundu-type equation are presented. As special cases of this result, the N-soliton solution of the Kaup-Newell equation, Chen-Lee-Liu equation, and Gerjikov-Ivanov equation can be obtained respectively by choosing different parameters.     

Nonstationary Maxwell equations

ABSTRACT

The paper deals with a mixed problem for nonstationary generalised Maxwell equations. The boundary conditions are of Riemann-Hilbert type. The problem is reduced to a mixed problem for a wave equation where the boundary conditions are of Dirichlet type as they were introduced by D. Spencer in the middle 1950?s. We use the Fourier method to construct an approximate solution to the problem in certain function spaces of Sobolev type.     

定态耦合Harry-Dym方程的Bargmann坐标及约束系统的Poisson结构

该文首先给出相联于耦合Harry-Dym(CHD)族的Lenard递归方程的多项式解,并证明了任一定态CHD方程的解均有可积的Bargmann坐标表示.最后讨论了约束系统的动力r-矩阵及Poisson结构.     

一类新的矩阵型修正Korteweg-de Vries方程的Riemann-Hilbert方法与精确解北大核心CSCD

在本文中,一类新的矩阵型修正Korteweg-de Vries(简记为mmKdV)方程被首次通过RiemannHilbert方法研究,而且,这一方程可通过选取特殊的势矩阵来降阶为我们熟知的耦合型修正Kortewegde Vries方程.从方程对应的Lax对的谱分析入手,作者成功地建立了方程对应的Riemann-Hilbert问题.在无反射势的特殊条件下,mmKdV方程的精确解可由Riemann-Hilbert问题的解给出.而且,基于特殊势矩阵所对应的特殊对称性,作者可以对原有的孤子解进行分类,从而得到一些有趣的解的现象,比如呼吸孤子、钟形孤子等.     

Implicit solitary wave solutions of the generalized magma equation

The generalized magma equation, in which dispersion and nonlinearity are coupled together in a manner reminiscent of the Harry-Dym equation, is solved to indicate both periodic and aperiodic implicit solitary wave solutions. It is argued that the presence of an additional spatial derivative in the magma equation also permits explicit solitary wave solutions, a feature not shared by the Harry-Dym equation.     

On the Inverse Scattering Transform for the Kadomtsev-Petviashvili Equation

The initial value problem of the Kadomtsev-Petviashvili equation for one choice of sign in the equation has been recently investigated in the literature. Here we consider the other choice of sign. We introduce suitable eigenfunctions which though bounded are not analytic in the spectral parameter. This, in contrast to the known case, prevents us from formulating the inverse problem as a nonlocal Riemann-Hilbert boundary value problem. Nevertheless a suitable formulation is given and a formal solution is constructed via a linear integral equation.     

四元数分析中正则函数与非齐次n阶方程(■~n F)/(■z~n)=f的某些边值问题

主要讨论了四元数空间中正则函数与非齐次n阶方程(■~n F)/(■z~n)=f在超球上的Dirichlet问题和双圆柱上具有任意整数指标的Riemann-Hilbert问题,给出了可解条件和解的积分表示式.     

Mortar Finite Volume Method with Adini Element for Biharmonic Problem

In this paper, we construct and analyse a mortar finite volume method for the discretization for the biharmonic problem in R2. This method is based on the mortar-type Adini nonconforming finite element spaces. The optimal order H2-seminorm error estimate between the exact solution and the mortar Adini finite volume solution of the biharmonic equation is established.     

Special Monodromy Groups and the Riemann-Hilbert Problem for the Riemann Equation

In this paper, we solve the Riemann-Hilbert problem for the Riemann equation and for the hypergeometric equation. We describe all possible representations of the monodromy of the Riemann equation. We show that if the monodromy of the Riemann equation belongs to SL(2, ℂ), then it can be realized not only by the Riemann equation, but also by the more special Riemann-Sturm-Liouville equation. For the hypergeometric equation, we construct a criterion for its monodromy group to belong to SL(2, ℤ).__________Translated from Matematicheskie Zametki, vol. 77, no. 5, 2005, pp. 753–767.Original Russian Text Copyright ©2005 by V. A. Poberezhnyi.     

四元数分析中T_Gf算子的Hlder连续性和Riemann-Hilbert边值问题

本文证明了四元数分析中的有界区域G上的非齐次Dirac方程u=f的分布解T_Gf,当f∈L_P(G),P>4时,在G上具有Holder连续性,讨论了超球和双圆柱上的方程u=f的Riemann-Hilbert边值问题,给出了可解条件和通解的积分表示,并且还证明了通解的Holder连续性。