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We find the form of all subnormal solutions of equation (1.4). Our results generalize and improve a well-known result of Wittich about equation (1.1). Several examples are given. Higher order equations are discussed.  相似文献   

3.
Siberian Mathematical Journal - Under study are the systems of nonlinear delay differential equations of neutral type with periodic coefficients of linear terms. We establish sufficient conditions...  相似文献   

4.
The present paper does not introduce a new approximation but it modifies a certain known method. This method for obtaining a periodic approximation of a periodic solution of a linear nonhomogeneous differential equation with periodic coefficients and periodic right-hand side is used in technical practice. However, the conditions ensuring the existence of a periodic solution may be violated and therefore the purpose of this paper is to modify the method in order that these conditions remain valid.  相似文献   

5.
李明星  肖丽鹏 《应用数学》2013,26(1):134-139
本文研究关于亚纯系数的非齐次线性微分方程的复振荡,得到方程f(k)+ak-1fk-1+…+a0f=F(a0,a1,…,ak-1和F是亚纯函数)具有一个振荡解空间,其空间中所有解的零点收敛指数为∞,至多除去一个例外值.  相似文献   

6.
Bäcklund transformations relating the solutions of linear PDE with variable coefficients to those of PDE with constant coefficients are found, generalizing the study of Varley and Seymour [2]. Auto-Bäcklund transformations are also determined. To facilitate the generation of new solutions via Bäcklund transformation, explicit solutions of both classes of the PDE just mentioned are found using invariance properties of these equations and other methods. Some of these solutions are new.  相似文献   

7.
We consider perturbed linear systems of difference equations with periodic coefficients. The zero solution of a nonperturbed system is assumed asymptotically stable, i.e., all eigenvalues of the monodromy matrix belong to the unit disk {||<1}. We obtain conditions on the perturbation of this system under which the zero solution of the system is asymptotically stable and also establish continuous dependence of one class of numeric characteristics of asymptotic stability of solutions on the coefficients of the system.  相似文献   

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本文以Cg空间为相空间,证明了具无限时滞D算子型线性中立型泛函微分方程存在周期解当且仅当存在有界解,得到了与以往结论互不包含的结果.  相似文献   

10.
具无限时滞线性中立型泛函微分方程周期解   总被引:6,自引:0,他引:6  
范猛  王克 《数学学报》2000,43(4):695-702
本文证明了具无限时滞D算子型线性中立型泛函微分方程存在周期解当且仅当存在有界解,推广了MasseraJ.L,ChowS.N.和MakayM.的结果.  相似文献   

11.
In this paper we shall introduce new constructions of approximate solutions of general linear partial differential equations with constant coefficients on the whole spaces, and establish fundamental estimates of the solutions depending on the inhomogeneous terms. This will be done by combining general ideas of the Tikhonov regularization and discretization of bounded linear operator equations on reproducing kernel Hilbert spaces. Furthermore, we will provide approximate solutions for the related inverse source problems.  相似文献   

12.
高仕安 《应用数学》2000,13(4):106-110
周期线性微分方程某解f(z)和f(z qω)的线性相关性是方程复振研究的起步关键,其中ω是方程系数的周期,q是某正整数。S.Bank和J.Langley于1992年证明了重要结果,但其优势条件有时不适用。本文提出“组合优势条件”产用其发展了这一结果,大大扩充了其适用性。  相似文献   

13.
Lagrange's variation-of-constants method for solving linear inhomogeneous ordinary differential equations (ode's) is replaced by a method based on the Loewy decomposition of the corresponding homogeneous equation. It uses only properties of the equations and not of its solutions. As a consequence it has the advantage that it may be generalized for partial differential equations (pde's). It is applied to equations of second order in two independent variables, and to a certain system of third-order pde's. Therewith all possible linear inhomogeneous pde's are covered that may occur when third-order linear homogeneous pde's in two independent variables are solved.  相似文献   

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Siberian Mathematical Journal - Under consideration is some class of systems of nonlinear differential equations. The exponentially dichotomous linear part of the systems is assumed to have...  相似文献   

16.
讨论一类高阶亚纯系数非齐次线性微分方程解的零点问题,当方程的系数A0是亚纯函数且满足δ(∞,A0)=δ(0)和lim(r→∞)log T(r,Ao)/log r=∞时,如果f1和f2是方程f((k))+A(κ—1)f((k—1))+…+Aof=F的两个线性无关解,得到max{λ(f1),λ(f2)}=∞.还考虑了σ(F)=∞或Ad(1dκ—1)满足lim(r→∞)log m(r,Ad)/log r=∞的情况.  相似文献   

17.
周期系数的高维Riccati方程的周期解   总被引:2,自引:0,他引:2  
黎雄 《数学进展》1999,28(4):313-322
本文研究了周期系数的高维Riccati方程X’=X·A(t)·X+B(t)·X+C(t),其中X∈R(n×1)A(t)∈R(1×n),B(t)∈R(n×n),C(t)E∈R(n×1);A(t),B(t),C(t)均是以2π为周期的实连续矩阵或向量函数,建立了该方程存在广义周期解的一个充要条件和存在周期解的两个充分条件,推广了周期系数的Riccati方程存在周期解的一些结论.  相似文献   

18.
Ukrainian Mathematical Journal - For systems of linear differential equations whose dimension can be lowered, we estimate the growth of meromorphic vector solutions. As an essentially new feature,...  相似文献   

19.
何静  郑秀敏 《应用数学》2013,26(1):114-124
本文研究亚纯系数的高阶线性微分方程,当方程系数满足一定条件时,得到方程的每一非零亚纯解具有无穷级且超级为n.此外,还研究了非齐次线性微分方程的亚纯解.  相似文献   

20.
Journal of Applied and Industrial Mathematics - We consider a system of nonlinear differential equations with distributed delay and periodic coefficients in the linear terms. Some sufficient...  相似文献   

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