二项自伴向量微分算子的本质谱

首先利用算子比较的方法,研究了二项自伴向量微分算子的本质谱,得到了这类微分算子的本质谱分布范围;然后利用算子分解定理,得到了这类算子谱的离散性的一个充分条件;最后得到了Sturm-Liouville算子和Schr?dinger算子的本质谱范围,以及这两类算子谱的离散性的一个充分条件.     

左定Sturm-Liouville算子的特征值计算(英文)

研究了定义在有限区间[a,b]上的具有分离型和混合型边界条件的左定正则Sturm-Liouville算子的特征值问题.把具有混合型边界条件的左定正则Sturm-Liouville问题转化成二维的、具有分离型边界条件的右定正则Sturm-Liouville问题,给出了具有混合型边界条件的左定正则Sturm-Liouville算子的特征值的数值计算方法.     

L^2[a,\infty)上高阶 Sturm-Liouville 算子下半有界性与谱

采用泛函分析与不等式渐近估计的方法,根据微分算子系数的特点,研究了高阶Sturm-Liouville微分算子下半有界性并得到其为下半有界的一些判定准则,同时给出了其下界的估计.这些结果对研究微分算子的谱是有益的.     

L2[α,∞)上高阶Sturm-Liouville算子下半有界性与谱

采用泛函分析与不等式渐近估计的方法,根据微分算子系数的特点,研究了高阶Sturm-Liouville微分算子下半有界性并得到其为下半有界的一些判定准则,同时给出了其下界的估计.这些结果对研究微分算子的谱是有益的.     

奇型Sturm-Liouville微分算子的极大增生扩张

应用扩展的Phillips理论及Brown和Krall关于共轭微分算式的构造原理,本文给出了奇型Sturm-Liouville 微分算子所有极大增生扩张的微分算式及定义域。     

奇型Sturm-Liouville微分算子的极大增生扩张

应用扩展的Phillips理论及Brown和Krall关于共轭微分算式的构造原理,本文给出了奇型Sturm-Liouville微分算子所有极大增生扩张的微分算式及定义域.     

具有算子系数的微分算子新的Ambarzumyan定理(英文)

有限区间上具有Neumann边界条件的Sturm-Liouville问题的谱可以唯一确定势函数,这就是经典的Ambarzumyan定理.本文将经典的Ambarzumyan定理推广到有限区间上具有算子系数的二阶与四阶微分算子中.     

边界条件中带有谱参数的不连续Sturm-Liouville算子的特征值问题

本文研究了具有转移条件且边界条件含特征参数的Sturm-Liouville算子L的特征值问题.首先,使用微分算子谱分析经典的方法,得到λ是该边值问题的特征值的充要条件,证明了该边值问题最多有可数个实的特征值、没有有限值的聚点.其次,通过渐近估计证得,所研究的Sturm-Liouville算子L有可数个离散的特征值且下方有界.     

Left-definite boundary conditions of a class of fourth-order singular differential operators

利用左定微分算子与相应的右定微分算子之间的关系来研究左定微分算子.首先给出四阶奇异微分算子的自共轭域;接着利用主解与Friedrichs扩张寻找最小算子的正的自共轭扩张;最后通过系数、区间端点和边界条件给出四阶奇异微分算子左定性的充要条件以及相应的左定边值矩阵的情形.     

具有转移条件的两个区间Sturm-Liouville算子的Green函数和渐近展开(英文)

考虑具有转移条件的两个区间Sturm-Liouville算子.定义与转移条件相关联的的Hilbert空间,并在新Hilbert空间里讨论两个区间Sturm-Liouville算子.进一步构造具有转移条件的两个区间Sturm-Liouville算子的Green函数,并且给出两个区间Sturm-Liouville算子的特征值和特征函数的渐近展开.     

复系数2n阶微分算子的谱

本文研究了复系数２ｎ阶微分算式（２．１）生成的Ｊ－自伴微分算子谱,对两类微分算子的本质谱,离散谱作了定性研究,得到了所生成微分算子本质谱的存在范围,以及所生成微分算子的谱是离散的充分条件．     

Spectral analysis of singular ordinary differential operators with indefinite weights

In this paper we develop a perturbation approach to investigate spectral problems for singular ordinary differential operators with indefinite weight functions. We prove a general perturbation result on the local spectral properties of selfadjoint operators in Krein spaces which differ only by finitely many dimensions from the orthogonal sum of a fundamentally reducible operator and an operator with finitely many negative squares. This result is applied to singular indefinite Sturm-Liouville operators and higher order singular ordinary differential operators with indefinite weight functions.     

奇型Sturm-Liouville算子的半逆问题

奇型Sturm-Liouville问题的势函数q(x)由两组谱唯一确定的,Sturm-Liouville算子的半逆问题讨论由一组谱和一半势函数唯一确定势函数q(x).本文利用Koyunbakan和Panakhov的方法,证明一组谱和(π/2,π)上的势函数q(x)唯一确定(0,π)上Sturm-Liouville方程含有奇型的1sin2x的势函数q(x).     

A-priori bounds and asymptotics on the eigenvalues in bifurcation problems for perturbed self-adjoint operators

We prove upper and lower bounds on the eigenvalues and discuss their asymptotic behaviour (as the norm of the eigenvector tends to zero) in bifurcation problems from the line of trivial solutions, considering perturbations of linear self-adjoint operators in a Hilbert space. The proofs are based on the Lyapounov-Schmidt reduction. The results are applied to a class of semilinear elliptic operators in bounded domains of RN and in particular to Sturm-Liouville operators.     

On the similarity of a <Emphasis Type="Italic">J</Emphasis>-nonnegative Sturm-Liouville operator to a self-adjoint operator

In terms of Weyl-Titchmarsh m-functions, we obtain a new necessary condition for an indefinite Sturm-Liouville operator to be similar to a self-adjoint operator. This condition is used to construct examples of J-nonnegative Sturm-Liouville operators with singular critical point zero.     

EIGENVALUES OF STURM-LIOUVILLE OPERATOR WITH GENERAL BOUNDARY CONDITIONS

We study the asymptotic behavior for the eigenvalues of Sturm-Liouville operators with smooth potential.The precise asymptotic expressions for the eigenvalues of the operators with general boundary conditions are given.     

Dependence of eigenvalues of regular Sturm-Liouville operators on the boundary condition

In this paper, we study the continuous dependence of eigenvalue of Sturm-Liouville differential operators on the boundary condition by using of implicit function theorem. The work not only provides a new and elementary proof of the above results, but also explicitly presents the expressions for derivatives of the n-th eigenvalue with respect to given parameters. Furthermore, we obtain the new results of the position and number of the generated double eigenvalues under the real coupled boundary condition.