Long time behavior of solutions of Davey-Stewartson equations

1. IntroductionIn the present paper we study the following Davey-Stewartson systemsupplemented with boundary conditionsand initial conditionwhere a = al la2, b = hi fo2, p = gi iap2, 7 = 71 iap and X = FI ixZ are complexconstallts, fi C RZ is a smooth bounded domain. The system was derived by Davey etalll] to model the evolution of a three-dimensional disturbance in the nonlinear regime ofplane Poiseuille flow (fully developed steady flow under a constallt pressure gradient betwe…     

Solution of Davey-Stewartson equations by homotopy perturbation method

In this paper, we extend the homotopy perturbation method to solve the Davey-Stewartson equations. The homotopy perturbation method is employed to compute an approximation to the solution of the equations. Computation the absolute errors between the exact solutions of the Davey-Stewartson equations and the HPM solutions are presented. Some plots are given to show the simplicity the method. The article is published in the original.     

代数微分方程的代数解

Using value distribution theory and techniques,the problem of the algebroid solutions of second order algebraic differential equation is investigated. Examples show that the results are sharp.     

Blow-up Dynamics of L~2 Solutions for the Davey–Stewartson System

We study the blow-up solutions for the Davey–Stewartson system(D–S system, for short)in L2x(R2). First, we give the nonlinear profile decomposition of solutions for the D–S system. Then, we prove the existence of minimal mass blow-up solutions. Finally, by using the characteristic of minimal mass blow-up solutions, we obtain the limiting profile and a precisely mass concentration of L2 blow-up solutions for the D–S system.     

Generalized dromion solutions of a new higher dimensional soliton equation

Introduction Since the pioneering work of Boiti et al.II], the study of soliton-laal structures in highdimensions has attracted much more attation. In particular, for some (2+l)-dimensional integrable models such as the Davey-Stewartson (DS) equationlZ], Kadomtsev- Petviashvill (K P )equation['], Nizhnili- Novikov- VeSelov (NNV) equationI4], the (2 + 1 ) -dimensional breajdng soliton equ&tionl'1, the (2+1)-dimensional long dispersive wave equationI6] and the scalar nonlinearSchrsdinger…     

Davey-Stewartson系统粗糙爆破解的极限行为

研究了Davey-Stewartson系统(简记为D-S系统)粗糙爆破解的动力学性质.所谓粗糙爆破解即为正则性为H~s(s1)的爆破解,此时D-S系统粗糙解不再满足能量守恒率.利用I-方法与Profile分解理论,得到了D-S系统粗糙爆破解在H~s(R~2)(其中ss_0,且s_0≤(1+11~(1/2))/5≈0.8633)中的极限行为,包括L~2强极限的不存在性与L~2集中性质以及极限图景.     

关于非线性Davey-Stewartson方程的散射理论

本文讨论具有三个非线性项的Davey-Stewartson方程的散射算子在整个能量空间H~1中存在。     

Existence of solutions for the MHD-Leray-alpha equations and their relations to the MHD equations

In this paper we derive some new equations and we call them MHD-Leray-alpha equations which are similar to the MHD equations. We put forward the concept of weak and strong solutions for the new equations. Whether the 3-dimensional MHD equations have a unique weak solution is unknown, however, there is a unique weak solution for the 3-dimensional MHD-Leray-alpha equations. The global existence of strong solution and the Gevrey class regularity for the new equations are also obtained. Furthermore, we prove that the solutions of the MHD-Leray-alpha equations converge to the solution of the MHD equations in the weak sense as the parameter ε in the new equations converges to zero.     

广义Davey-Stewartson方程的孤波解

在本文中,利用辅助的常微分方程来代替更一般的方程,扩张映射方法被呈现.通过这种方法,使用符号计算关于Davey-Stewartson方程的许多新的孤波解被构造.     

Davey-Stewartson方程的同宿轨道

研究了Davey-Stewartson方程的同宿轨道解的问题,利用Hirota方法,通过给出的相关变换,构造出Davey-Stewartson方程的同宿解,给出了同宿解的解析表达式,并讨论了Davey-Stewartson的同宿轨道．     

New exact solutions to breaking soliton equations and Whitham-Broer-Kaup equations

In this paper, by using the improved Riccati equations method, we obtain several types of exact traveling wave solutions of breaking soliton equations and Whitham-Broer-Kaup equations. These explicit exact solutions contain solitary wave solutions, periodic wave solutions and the combined formal solitary wave solutions. The method employed here can also be applied to solve more nonlinear evolution equations.     

Dromion solutions for dispersive long-wave equations in two space dimensions

By using the homogeneous balance method, we show that the dromion solutions exist for the (2+1)-dimensional dispersive long-wave equations. It is conjectured that the method used here can be generalized to a class of nonlinear evolution equation. The method here is very concise and primary.     

The sharp threshold and limiting profile of blow-up solutions for a Davey-Stewartson system

The blow-up solutions of the Cauchy problem for the Davey-Stewartson system, which is a model equation in the theory of shallow water waves, are investigated. Firstly, the existence of the ground state for the system derives the best constant of a Gagliardo-Nirenberg type inequality and the variational character of the ground state. Secondly, the blow-up threshold of the Davey-Stewartson system is developed in R³. Thirdly, the mass concentration is established for all the blow-up solutions of the system in R². Finally, the existence of the minimal blow-up solutions in R² is constructed by using the pseudo-conformal invariance. The profile of the minimal blow-up solutions as t→T (blow-up time) is in detail investigated in terms of the ground state.     

A direct method of construction of two-zone solutions of nonlinear equations

We suggest an approach that allows one to effectively construct two-zone solutions, including real, of some nonlinear equations without applying the technique of algebraic curves. Thestarting point in the construction is a special addition theorem for theta-functions of two variables. The method is illustrated by the Kadomtsev-Petviashvili, KdV, and sine-Gordon equations. Translated fromMatematicheskie Zametki, Vol. 66, No. 3, pp. 401–406, September, 1999.     

Discrete exact solutions of modified Volterra and Volterra lattice equations via the new discrete sine-Gordon expansion algorithm

Recently, we have presented a sine-Gordon expansion method to construct new exact solutions of a wide of continuous nonlinear evolution equations. In this paper we further develop the method to be the discrete sine-Gordon expansion method in nonlinear differential-difference equations, in particular, discrete soliton equations. We choose the modified Volterra lattice and Volterra lattice equation to illustrate the new method such as many types of new exact solutions are obtained. Moreover some figures display the profiles of the obtained solutions. Our method can be also applied to other discrete soliton equations.     

广义Davey-Stewartson系统驻波的强不稳定性

本文研究方程驻波的强不稳定性iu_t+△u+a|u|~(p-1)u+E_1(|u|~2)u=0,t≥0,x∈R~n,其中a0,1p(n+2)/(n+2)~+,n∈{2,3}.当1+4/n≤pn+2/(n-2)~+)时,文[Sharp threshold of global existence and instability of standing wave for a Davey-Stewartson system,Commun.Math.Phys.,2008,283:93-125]在驻波的频率满足一定假设条件下,证明了此方程驻波的强不稳定性.本文去掉这个假设,得到相同的结论.     

Uniqueness of weak solutions of the Navier-Stokes equations

Consider the Navier-Stokes equation with the initial data a ∈ L _σ ²(ℝ ^d ). Let u and v be two weak solutions with the same initial value a. If u satisfies the usual energy inequality and if ∇v ∈ L ²((0, T); (ℝ ^d ) ^d ) where (ℝ ^d ) is the multiplier space, then we have u = v.     

Finite-gap solutions of boundary value problems for integrable equations

Translated from Matematicheskie Zametki, Vol. 48, No. 2, pp. 10–18, August, 1990.     

Existence of solutions and Gevrey class regularity for Leray-alpha equations

In this paper we consider some equations similar to Navier-Stokes equations, the three-dimensional Leray-alpha equations with space periodic boundary conditions. We establish the regularity of the equations by using the classical Faedo-Galerkin method. Our argument shows that there exist an unique weak solution and an unique strong solution for all the time for the Leray-alpha equations, furthermore, the strong solutions are analytic in time with values in the Gevrey class of functions (for the space variable). The relations between the Leray-alpha equations and the Navier-Stokes equations are also considered.     

On the initial value problem and scattering of solutions for the generalized Davey-Stewartson systems

We study the initial value problem of the Davey-Stewartson systems for the elliptic-elliptic and hyperbolic-elliptic cases. The local and global existence and uniqueness of solutions in H^s is shown. Also, we prove that the scattering operator carries a band in H^s into H^s.