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Aiping Wang 《Journal of Functional Analysis》2008,255(6):1554-1573
There are three basic types of self-adjoint regular and singular boundary conditions: separated, coupled, and mixed. For even order problems with real coefficients, one regular endpoint and arbitrary deficiency index d, we give a construction for each type and determine the number of possible conditions of each type under the assumption that there are d linearly independent square-integrable solutions for some real value of the spectral parameter. In the separated case our construction yields non-real conditions for all orders greater than two. It is well known that no such conditions exist in the second order case. Our construction gives a direct alternative to the recent construction of Everitt and Markus which uses the theory of symplectic spaces. We believe our construction will prove useful in the spectral analysis of these operators and in obtaining canonical forms of self-adjoint boundary conditions. Such forms are known only in the second order, i.e. Sturm-Liouville, case. Even for regular problems of order four no such forms are available. 相似文献
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Xiaoling Hao Jiong Sun Anton Zettl 《Journal of Mathematical Analysis and Applications》2012,387(2):1176-1187
Canonical forms of regular self-adjoint boundary conditions for differential operators are well known in the second order i.e. Sturm–Liouville case. In this paper we find canonical forms for fourth order self-adjoint boundary conditions. 相似文献
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Aiping Wang 《Journal of Mathematical Analysis and Applications》2011,378(2):493-506
For general even order linear ordinary differential equations with real coefficients and endpoints which are regular or singular and for arbitrary deficiency index d, the self-adjoint domains are determined by d linearly independent boundary conditions. These conditions are of three types: separated, coupled, and mixed. We give a construction for all conditions of each type and determine the number of conditions of each type possible for a given self-adjoint domain. Our construction gives a direct alternative to the recent construction of Everitt and Markus which uses the theory of symplectic spaces. We believe our construction will prove useful in the spectral analysis of these operators and in obtaining canonical forms of self-adjoint boundary conditions. Such forms are known only in the second order, i.e. Sturm-Liouville, case. Even for regular problems of order four no such forms are available. In the case when all d conditions are separated this construction yields explicit non-real conditions for all orders greater than two. It is well known that no such conditions exist in the second order case. 相似文献
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Canonical forms of boundary conditions are important in the study
of the eigenvalues of boundary conditions and their numerical
computations. The known canonical forms for self-adjoint differential
operators, with eigenvalue parameter dependent boundary conditions,
are limited to 4-th order differential operators. We derive
canonical forms for self-adjoint $2n$-th order differential
operators with eigenvalue parameter dependent boundary conditions.
We compare the 4-th order canonical forms to the canonical forms
derived in this article. 相似文献
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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. 相似文献
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An equivalence between a class of regular self-adjoint fourth-order boundary value problems with coupled or mixed boundary conditions and a certain class of matrix problems is investigated. Such an equivalence was previously known only in the second-order case and fourth-order case with separated boundary conditions. 相似文献
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本文研究具有混合型边界条件的左定Sturm-Liouvile问题特征值的下标计算问题.首先给出具有分离型边界条件和混合型边界条件的左定Sturm-Liouville问题的特征值之间的不等式;然后利用这个结果给出一种计算混合型边界条件下左定Sturm-Liouville问题特征值下标的方法. 相似文献
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We describe a new algorithm to compute the eigenvalues of singular Sturm-Liouville problems with separated self-adjoint boundary conditions for both the limit-circle nonoscillatory and oscillatory cases. Also described is a numerical code implementing this algorithm and how it compares with SLEIGN. The latter is the only effective general purpose software available for the computation of the eigenvalues of singular Sturm-Liouville problems. 相似文献
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We describe a new algorithm to compute the eigenvalues of singular Sturm-Liouville problems with separated self-adjoint boundary conditions for both the limit-circle nonoscillatory and oscillatory cases. Also described is a numerical code implementing this algorithm and how it compares with SLEIGN. The latter is the only effective general purpose software available for the computation of the eigenvalues of singular Sturm-Liouville problems. 相似文献
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Guixia Wang Zhong Wang Hongyou Wu 《Journal of Computational and Applied Mathematics》2008,220(1-2):490-507
The main purpose of the EIGENIND-SLP codes is to compute the indices of known eigenvalues of self-adjoint Sturm–Liouville problems with coupled boundary conditions (BCs). The spectrum of the problems can be unbounded from both below and above. Using some recent theoretical results, the computation is converted to that of the indices of the same eigenvalues for appropriate separated BCs, and is then carried out in terms of the Prüfer angle. The algorithm so generated and its implementation are discussed, and numerous examples are presented to illustrate the theoretical results and various aspects of the implementation. 相似文献
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We prove a stability theorem for the eigenvalues of general non-negative self-adjoint linear operators with compact resolvents and by applying it we prove a sharp stability result for the dependence of the eigenvalues of second order uniformly elliptic linear operators with homogeneous Neumann boundary conditions upon domain perturbation. 相似文献
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《Applied Mathematics Letters》2002,15(4):459-463
This paper is an extension to our work on the computation of the eigenvalues of regular fourth-order Sturm-Liouville problems using Fliess series. The purpose here is twofold. First, we consider general self-adjoint separated boundary conditions. Second, we modify the algorithm presented in an earlier paper to ease considerably the computation of the iterated integrals involved. 相似文献
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The dependence of the eigenvalues of self-adjoint Sturm–Liouville problems on the boundary conditions when each endpoint is regular or in the limit-circle case is now, due to some surprisingly recent results, well understood. Here we study this dependence for singular problems with one endpoint in the limit-point case. 相似文献
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Ekin Uğurlu 《Mathematical Methods in the Applied Sciences》2020,43(5):2202-2215
In this paper, we consider some singular formally symmetric (self-adjoint) boundary value problems generated by a singular third-order differential expression and separated and coupled boundary conditions. In particular, we consider that the minimal symmetric operator generated by the third-order differential expression has the deficiency indices (3,3). We investigate same spectral properties related with these problems, and we introduce a method to find the resolvent operator. 相似文献
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In the case of a general nonlinear self-adjoint spectral problem for systems of ordinary differential equations with boundary
conditions independent of the spectral parameter, we introduce the notion of the number of an eigenvalue. Methods for the
computation of the numbers of eigenvalues lying in a given range of the spectral parameter and for finding the eigenvalue
with a given number, which were earlier suggested by the author for Hamiltonian systems, are generalized to the considered
problem. We introduce the notion of an index of a problem for a general nontrivially solvable linear homogeneous self-adjoint
boundary value problem. 相似文献
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常型Sturm-Liouville问题的左定边值条件 总被引:2,自引:0,他引:2
本文刻画了常型Sturm-Liouville问题的左定边值条件.通过Sturm-Liouville微分算式的系数、区间端点以及边值条件给出了其左定性的充要条件.应用自伴边值条件分类,确切地给出了所有可能的左定边值条件. 相似文献
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We consider an inverse boundary problem for a general second order self-adjoint elliptic differential operator on a compact differential manifold with boundary. The inverse problem is that of the reconstruction of the manifold and operator via all but finite number of eigenvalues and traces on the boundary of the corresponding eigenfunctions of the operator. We prove that the data determine the manifold and the operator to within the group of the generalized gauge transformations. The proof is based upon a procedure of the reconstruction of a canonical object in the orbit of the group. This object, the canonical Schrödinger operator, is uniquely determined via its incomplete boundary spectral data. 相似文献