Calculating the minimal/maximal eigenvalue of symmetric parameterized matrices using projection

In applications of linear algebra including nuclear physics and structural dynamics, there is a need to deal with uncertainty in the matrices. We focus on matrices that depend on a set of parameters ω and we are interested in the minimal eigenvalue of a matrix pencil ( A , B ) with A , B symmetric and B positive definite. If ω can be interpreted as the realization of random variables, one may be interested in statistical moments of the minimal eigenvalue. In order to obtain statistical moments, we need a fast evaluation of the eigenvalue as a function of ω . Because this is costly for large matrices, we are looking for a small parameterized eigenvalue problem whose minimal eigenvalue makes a small error with the minimal eigenvalue of the large eigenvalue problem. The advantage, in comparison with a global polynomial approximation (on which, e.g., the polynomial chaos approximation relies), is that we do not suffer from the possible nonsmoothness of the minimal eigenvalue. The small‐scale eigenvalue problem is obtained by projection of the large‐scale problem. Our main contribution is that, for constructing the subspace, we use multiple eigenvectors and derivatives of eigenvectors. We provide theoretical results and document numerical experiments regarding the beneficial effect of adding multiple eigenvectors and derivatives.     

关于特征值与广义特征值的Bauer-Fike型相对扰动界

本文研究特征值与广义特征值的Bauer-Fike型相对扰动界.我们给出了一些新的结果.这些界从一定的意义上改进了以往相应的结论.     

斜对称双对角矩阵特征值反问题

讨论了关于斜对称双对角矩阵的特征值反问题．即：已知一个n阶斜对称双对角矩阵的特征值和两个n-1阶子矩阵的部分特征值，则可求得该矩阵．最后给出了数值例子．     

The formulation and numerical method for partial quadratic eigenvalue assignment problems

In this paper, we consider the minimum norm and robust partial quadratic eigenvalue assignment problems (PQEVAP). A complete theory on the existence of solutions for the PQEVAP is established. It is shown that solving the PQEVAP is essentially solving an eigenvalue assignment for a linear system of a much lower order, and the minimum norm and robust PQEVAPs are then concerning the minimum norm and robust eigenvalue assignment problems associated with this linear system. Based on this theory, an algorithm for solving the minimum norm and robust PQEVAPs is proposed, and its efficient behaviors are illustrated by some numerical examples. Copyright © 2010 John Wiley & Sons, Ltd.     

图的Laplacian特征值

本文研究了连通图的Laplacian特征值,利用图的Laplacian矩阵的特征多项式的行列式表示式,对存在两个不同顶点,但有相同邻集的一类图,得到了一个Laplacian特征值,并给出了它的应用.     

Rellich type identities for eigenvalue problems and application to the Pompeiu problem

For classical Neumann eigenvalue, buckling eigenvalue and clamped plate eigenvalue, we give the corresponding Rellich type identities. As an application of these results, then, we obtain a new necessary and sufficient condition for a domain without the Pompeiu property.     

复Monge－Ampere方程的特征值问题

讨论了复空间中强拟凸域上的复Ｍｏｎｇｅ－Ａｍｐｅｒｅ方程的特征值问题，证明了特征值问题解的存在唯一性，并给出了这个特征值与一类复空间中复Ｌａｐｌａｃｅ算子的第一特征值的关系，最后利用特征值及特征函数的存在性讨论了一类复Ｍｏｎｇｅ－Ａｍｐｅｒｅ方程的解的存在性及其分歧．     

具有四个状态的系统特征值的存在性

针对具有四个状态的系统所建立的模型,得出了系统算子一个特征值对应一个特征向量的结论,并证明了除0特征外还存在另外非零实特征值.     

DERIVATIVES OF EIGENPAIRS OF SYMMETRIC QUADRATIC EIGENVALUE PROBLEM

Derivatives of eigenvalues and eigenvectors with respect to parameters in symmetric quadratic eigenvalue problem are studied. The first and second order derivatives of eigenpairs are given. The derivatives are calculated in terms of the eigenvalues and eigenvectors of the quadratic eigenvalue problem, and the use of state space representation is avoided, hence the cost of computation is greatly reduced. The efficiency of the presented method is demonstrated by considering a spring-mass-damper system.     

可修复人机储备系统算子的本征值问题

讨论了可修复人机储备系统算子的本征值问题,讨论了系统算子非零本征值的存在性,并且系统算子一个本征值对应一个本征向量.     

The Problem of Eigenvalue on Noncompact Complete Riemannian Manifold

Let M be an n-dimensional noncompact complete Riemannian manifold, "Δ" is the Laplacian of M. It is a negative selfadjoint operator in L²(M). First, we give a criterion of non-existence of eigenvalue by the heat kernel. Applying the criterion yields that the Laplacian on noncompact constant curvature space form has no eigenvalue. Then, we give a geometric condition of M under which the Laplacian of M has eigenvalues. It implies that changing the metric on a compact domain of constant negative curvature space form may yield eigenvalues.     

M/M/1/m系统算子的本征值特性(m=7,8)

研究了m=7,8时,M/M/1/m算子本征值特性:相应本征值的代数重为1;m=7,8时,相应的系统算子的非零本征值相互交替;m=8时的最大非零本征值比m=7时更靠近0点.这种特性延续了m=1,2,3,4,5,6时相应的特性.另外给出了m=7,8时,相应的p_0(t)图像.     

M/M/1/m系统算子的本征值特性(m=4,5)

研究了m=4,5时,M/M/1/m算子本征值特性:二者相应本征值的代数重均为1;二者相应的系统算子的非零本征值相互交替;后者的最大非零本征值逐渐靠近0点;另外给出了m=4,5时,相应的p_0(t)图像.     

M/M/1/m系统算子的本征值特性(m=5,6)

研究了m=5,6时,M/M/1/m算子本征值特性:m=6时相应本征值的代数重为1;m=5,6时,相应的系统算子的非零本征值相互交替;m=6时的最大非零本征值比m=5时更靠近0点.这种特性延续了m=1,2,3,4,5时相应的特性.另外给出了m=5,6时,相应的po(t)图像.     

On the index of the boundary value problem for a homogeneous Hamiltonian system of differential equations

The index of the homogeneous self-adjoint boundary value problem for the Hamiltonian systems of ordinary differential equations is introduced. It is assumed that the system has a nontrivial solution. The relationship between the index of an eigenvalue of the nonlinear eigenvalue problem and the index of the corresponding homogeneous problem is established. Properties of the index of the problem and those of the eigenvalue are examined.     

A probabilistic approach to the first Dirichlet eigenvalue on non-compact Riemannian manifold

By using diffusion process with absorbing boundary, some lower bounds are obtained for the first Dirichlet eigenvalue of operator Δ+∇h on a non-compact complete Riemannian manifold. The resulting estimates contain McKean's estimate for ∇h=0. Moreover, the first Dirichlet eigenvalue for elliptic operators onR ^d and the first mixed eigenvalue are also studied. Some examples show that our estimates can be sharp even for ∇h≠0. Research supported in part by NFSC and the State Education Commission of China     

两不同部件并联可修系统的本征值问题

研究了两不同部件并联可修系统的一个本征值对应一个本征向量的问题以及求解了该系统算子非零解的存在.     

M/M/1/m系统算子的本征值特性(m=1,2,3,4)

研究了m=1,2,3,4时,M/M/1/m算子本征值特性:每个模型的相应本征值的代数重均为1;相邻两个模型系统算子的非零本征值相互交替;随着m值的增大,相应的最大非零本征值逐渐靠近0点;给出了m=3,4时,相应的p_0(t)图像.     

具有内部构造安全保障体系的冗余机器系统的特征值的问题

对具有内部构造安全保障体系的冗余机器系统中的特征值的存在性进行了分析求解,给出了实例,并对该系统的特征值进行了一个特征值对应一个特征向量的求征.     

Minimal least eigenvalue of connected graphs of order n and size m = n + k (5≤k≤8)

The least eigenvalue of a connected graph is the least eigenvalue of its adjacency matrix. We characterize the connected graphs of order n and size n + k (5≤k≤8 and n>k + 5) with the minimal least eigenvalue.