关于矩阵张量积的谱

<正> 设 A=(a_(jk))_(m_1×m_2),B=(b_(jk))_(n_1×n_2),则 m_1n_1×m_2n_2矩阵(?)称为 A 与 B 的张量积(也称直积或 Kronecker 积).矩阵的张量积是多重线性代数的重要工具之一,在群表示论中也有重要应用.本文的主要目的是在作者过去工作的基础上给出矩阵张量积的一些谱性质.     

块H-矩阵与块矩阵的谱

利用G-函数概念研究块H-矩阵,引入若干块矩阵概念。获得了块H-矩阵的等价刻划,得到了一般块矩阵特征值的由G-函数描述的分布域,由于用G-函数刻划,所获结果具有一般性。     

关于“块H-矩阵与块矩阵的谱”一文的注记

完善了"块H-矩阵与块矩阵的谱"一文中的主要结论.进一步,给出了分块矩阵特征值的一个新包含域,并用实例说明了新结论的优越性.     

Markov链大偏差与矩阵谱

本文研究可数状态Markov链的大偏差及相关问题,通过一种比较与控制的方法,探讨减弱对不可约性要求的可能性.这种途径还让我们从不同角度刻画了大偏差速率函数,得到它们与过程平稳分布之间的一些本质联系.特别地,本文证明有限状态链一定满足大偏差原理,其速率函数的(局部)极小值与链的转移矩阵的主特征值和特征向量密切相关.     

关于矩阵Kronecker积的谱半径的不等式

本证明了矩阵的Kronecker积的谱半径的两个不等式。     

关于矩阵Kronecker积的谱半径的不等式

本文证明了矩阵的 Kronecker积的谱半径的两个不等式     

矩阵分解与Chrestenson谱的计算

本文研究离散Fourier变换的一类变型-整数模合数m剩余类环上n元函数的Chrestenson谱的快速计算,基于稀疏矩阵分解,给出了两种复杂度为O(mⁿn∑^r_i=1p_i)的计算Chrestenson谱的快速算法,其中p₁p₂…p_r是m的素因子分解.     

关于随机矩阵Kronecker积的谱半径的不等式

研究了随机矩阵的Kronecker积的数学期望的性质,得到了随机矩阵的Kronecker积的谱半径的几个不等式.     

谱密度矩阵的对称谱窗估计

在平稳时间序列的谱分析中,估计谱密度的方法很多,谱窗估计法是常用的一种方法。采用这种方法的键是选择好的窗函数,同时要控制窗口的大小——窗函数平滑周期的范围。评选窗函数要有一个好坏的标准,例如谢衷洁与程乾生以分瓣率的高低作为评选时窗函数的标准来寻找最佳的时窗函数;作者在和中,适当控制某种对称窗口的大小,可使谱密度估计量具有渐近无偏和均方相合等优良性质,而对时间序列本身不作正态分布的假定。     

缺项算子矩阵的谱

本文对缺项算子矩阵 Ｌ＝ 的谱进行了一些深入的讨论,得出了σ（Ｌｘ）与 σ（Ｌｘ）的表示,这里 Ｌｘ＝     

On matrices having equal spectral radius and spectral norm

In this paper we characterize all nxn matrices whose spectral radius equals their spectral norm. We show that for n?3 the class of these matrices contains the normal matrices as a subclass.     

On spectral properties of multiparameter polynomial matrices

Spectral problems for multiparameter polynomial matrices are considered. The notions of the spectrum (including those of its finite, infinite, regular, and singular parts), of the analytic multiplicity of a point of the spectrum, of bases of null-spaces, of Jordan s-semilattices of vectors and of generating vectors, and of the geometric and complete geometric multiplicities of a point of the spectrum are introduced. The properties of the above characteristics are described. A method for linearizing a polynomial matrix (with respect to one or several parameters) by passing to the accompanying pencils is suggested. The interrelations between spectral characteristics of a polynomial matrix and those of the accompanying pencils are established. Bibliography: 12 titles. Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 229, 1995, pp. 284–321. Translated by V. B. Khazanov.     

On a spectral property of Jacobi matrices

Let be a Jacobi matrix with elements on the main diagonal and elements on the auxiliary ones. We suppose that is a compact perturbation of the free Jacobi matrix. In this case the essential spectrum of coincides with , and its discrete spectrum is a union of two sequences 2, x^-_j<-2$">, tending to . We denote sequences and by and , respectively.

The main result of the note is the following theorem.

Theorem.     Let be a Jacobi matrix described above and be its spectral measure. Then if and only if

-\infty,\qquad {ii)} \sum_j(x^\pm_j\mp2)^{7/2}<\infty. \end{displaymath}">

     

On the spectral radius and the spectral norm of Hadamard products of nonnegative matrices

We prove the spectral radius inequality ρ(A₁°A₂°?°A_k)?ρ(A₁A₂?A_k) for nonnegative matrices using the ideas of Horn and Zhang. We obtain the inequality ‖A°B‖?ρ(A^TB) for nonnegative matrices, which improves Schur’s classical inequality ‖A°B‖?‖A‖‖B‖, where ‖·‖ denotes the spectral norm. We also give counterexamples to two conjectures about the Hadamard product.     

On sharp bounds for spectral radius of nonnegative matrices

We give sharp upper and lower bounds for the spectral radius of a nonnegative matrix with positive row sums using average 3-row sums, compare these bounds with the existing bounds using the average 2-row sums by examples, and apply them to the adjacency matrix and the signless Laplacian matrix of a digraph or a graph.     

On a certain class of spectral characteristics of matrices

The research was financially supported by the Russian Foundation for Fundamental Research (Grant 93-011-1515).