LONG-TIME BEHAVIOR OF FINITE DIFFERENCE SOLUTIONS OF A NONLINEAR SCHRODINGER EQUATION WITH WEAKLY DAMPED

1. IntroductionThe nonlinear schr~r equation with weakly dampedwhere t = N, o > 0, together with appropriate boUndary and hatal condition, is ared inmany physical fields. The echtence of an attractor is one of the most boortant ~eristiCSfor a dissipative system. The long-tabs dynamics is completely determined by the attractorof the system. J.M. Ghidaglia[1] studied the lOng-the behavior of the nonlineaz Sequation (1.1) and proved the eAstence of a compact global attractor A in H'(n) which…     

一类带弱奇异核非线性偏积分微分方程的全离散有限元

1引言我们将研究下面一类带弱奇异核非线性偏积分微分方程的数值解:u_t-▽·(a(u)▽u)-integral from n=0 to tβ(t-s)△u(s)ds=f(u),x∈Ω,t∈(?),(1.1) u(·,t)=0,x∈(?)Ω,t∈J,(1.2) u(·,0)=v(x),x∈Ω,(1.3)其中Ω为平面上的凸角域,J=(0,T],α和f为R上的光滑函数,满足0相似文献   

一类非线性发展方程弱解的长时间性态

本文分别在全空间和半空间两种情形下讨论一类非线性发展方程弱解的长时间性态．证明了其弱解在L^2范数下衰减速率和线性热方程一致，分别为t^-n/2(1-r-1/2)和t^-n/2(1/r-1/2)-1/2。     

五次NLS方程全离散谱格式的大时间性态

Nonlinear Schroedinger equation arises in many physical problems. There are many works in which properties of the solution are studied. In this paper we use fully discrete Fourier spectral method to get an approximation solution of nonlinear weakly dissipative Schroedinger equation with quintic term. We give a large-time error estimate and obtain the existence of the approximate attractor A N^k.     

广义KdV-Burgers方程长时间性态的谱方法

1．引言随着无限维动力系统研究的发展和深入,人们对非线性发展方程长时间性态的研究越来越重视[1－6］,而这种研究在很大程度上依赖于数值计算的结果,因此,计算结果是否可靠,计算格式先得是否合适都是值得探讨和深入研究的问题17－10．广义KdV－Burg6rs方程是一类重要的非线性发展方程,在实际问题中也有着广泛的应用,因此,对它的研究即有理论价值也有实际意义．本文讨论如下的广义KdV－Burgers方程的周期初值问题其中a,q是已知实常数,且a＞0八。）,g（。）,h00是已知实函数．文［10］对上述问题构造了半离散的Fourier谱逼近…     

Ginzburg-Landau方程动力性态的Fourier谱逼近

0　引言和符号立方Schrodinger方程或更一般的形式Ginzburg-Landau方程出现在许多物理和化学问题中.例如在非线性光学的细束流中有方程2ikux+2⊥u+n2n0k2|u|2u=0对于二维流,有方程n2n0k2|u|2u=-2kiut-uxx-uyy还有等离子体的Langmuir波;一维单色波的自调制;二维定态平面波的自聚集;在非相对论下超导电子对在电磁场中运动等均可用非线性Schrodinger方程和Ginzburg-Landau方程来描述[1-4].另外,反应扩散方程描述的化学反应方程的研究中也出现Ginzburg-Landau方程,如相对于稳态浓度c*的扰动浓度c-c*就满足Ginzburg-Landau方程[5,6].由…     

A LEAP FROG FINITE DIFFERENCE SCHEME FOR A CLASS OF NONLINEAR SCHRODINGER EQUATIONS OF HIGHORDER

1.IntroductionItiswellknowthatthenonlinearequationsofSchr6dingertypeareofgreatimportancetophysicsandcanbeusedtodescribeextensivephysicalphenomenatll.InthispapergwewillconsidertheperiodicinitialvalueproblemforthefollowingclassofnonlinearSchrodingerequationofhighorder:wherem',MandMIareallpositiveconstant.Inthepaper[2])therehavediscussedinitialValueproblemofsystemsuchas(1.1)(1.3),introducedadifferenceschemeofconservationtype,andresearcheditsstabilityandconvergence.Otherwise,itisanimplicitmetho…     

一类偏积分微分方程二阶差分全离散格式

本文给出了数值求解一类偏积分微分方程的二阶差分全离散格式．时间方向采用了二阶向后差分格式,积分项的离散利用了Lubich的二阶卷积求积公式,给出了稳定性的证明、误差估计及收敛性的结果,并给出了数值例子．     

A FINITE DIFFERENCE METHOD FOR THE HEAT EQUATION WITH A NONLINEAR BOUNDARY CONDITION

This article is concerned with the numerical solution to a parabolic equation with a kind of nonlinear boundary conditions. A difference scheme is constructed by the method of reduction of order on uniform mesh to solve the problem. It is proved that the difference scheme is uniquely solvable and uncon-ditionaUy convergent with the convergence order 2 in both space and time in an energy norm. An effective iterative algorithm is given and a numerical example is presented to demonstrate the theoretical results.     

热方程非线性边界条件问题的有限差分方法

This article is concerned with the numerical solution to a parabolic equation with a kind of nonlinear boundary conditions. A difference scheme is constructed by the method of reduction of order on uniform mesh to solve the problem. It is proved that the difference scheme is uniquely solvable and uncon-ditionaUy convergent with the convergence order 2 in both space and time in an energy norm. An effective iterative algorithm is given and a numerical example is presented to demonstrate the theoretical results.     

二阶变系数椭圆型微分方程谱方法的后验误差估计

As to the posteriori error of spectral method for second order elliptic differential equation of variable coefficient,we construct two easy solvable differential equations of constant coefficient. Among the two energy norms of the solutions of two differential equations, one is larger than the energy norm of exact error ,another is smaller than the energy norm of exact error, and the two energy norms of the solutions are of same order.     

一类半线性抛物型方程全离散Chebyshev拟谱逼近的大时间性态

In the paper, the nonperidic initial value problem for a class of semilinear parabolic equations is considered. We construct the full discrete Chebyshev pseudospectral scheme and analyze the error of approximate solution for it. We obtain the error estimation on large time using the local continuation method and the existence of approximate global attractor.     

非线性分数阶反应扩散方程组的间断时空有限元方法

利用时间间断空间连续的时空有限元方法构造了空间分数阶反应扩散方程组的可以逐时间层求解的全离散格式.在时间离散区间上,采用Radau积分公式,将插值理论与有限元理论相结合,给出了全离散格式解的存在唯一性结果,并证明了所给格式是无条件稳定的,进而详细给出最优阶L~∞(L~2)模误差估计过程.最后用数值算例验证了理论分析的正确性.     

高维广义Kuramoto-Sivashinsky型方程全离散Fourier拟谱方法的大时间性态研究

在文~[1]中我们用Fourier拟谱方法讨论了广义Kuramoto-sivashinsky型方程的半离散近似解，得到了近似解的大时间误差估计、近似吸引子的存在性和收敛性。当进一步关于时间离散时，必须考虑全离散格式的大时间性态，由于原方程的解关于时间的导数u_1在t=     

带非线性源项的双侧空间分数阶扩散方程的隐式中点方法

本文用隐式中点方法离散一阶时间偏导数,并用拟紧差分算子逼近Riemann-Liouville空间分数阶偏导数,构造了求解带非线性源项的空间分数阶扩散方程的数值格式.给出了数值方法的稳定性和收敛性分析.数值试验表明数值方法是有效的.     

用非线性方程组求解等式约束非线性规划问题的降维算法

本文研究线性和非线性等式约束非线性规划问题的降维算法.首先,利用一般等式约束问题的降维方法,将线性等式约束非线性规划问题转换成一个非线性方程组,解非线性方程组即得其解;然后,对线性和非线性等式约束非线性规划问题用Lagrange乘子法,将非线性约束部分和目标函数构成增广的Lagrange函数,并保留线性等式约束,这样便得到一个线性等式约束非线性规划序列,从而,又将问题转化为求解只含线性等式约束的非线性规划问题.     

具有跳扩散的美式期权二叉树计算格式的收敛速率

American put option with jump-diffusion can be modelled as a vari- ational inequality problem with an integral term.Under the stability condition (σ~2Δt)/(Δx~2)≤1,whereΔx=ln(S_n 1)/(S_n),the convergence rate O((Δx)~(2/3) (Δt)~(1/3))of the explicit finite scheme for this problem is obtained by using penalization technique. The binomial tree scheme of this model,which is equivalent to the explicit scheme, is convergent by the same rate.