关于方阵特征值扰动的两个注记

Two Notes on the Variation of the Spectrum of a Matrix

第一部分将孙继广教授的结果推广,得到任意方阵特征值扰动的一个结果与若干推论.第二部分,给出了对称矩阵加上一个对称矩阵后,所得矩阵之特征值的表示.

Problem on the variation of the spectrum of a matrix often gives intense interest.The aim of this paper is to give two notes on such problem.The first part of this paper give a note on the variation of the spectrum of an arbitrary matrix,and in second part of it,a note on characterization of eigenvalues of a symmetric matrix perturbed by a symmetric matrix is given.