缺项3×3阶上三角算子矩阵的可能点谱

Possible point spectra of 3×3 partial upper triangular operator matrices

基于值域的稠密性和闭性,有界线性算子的点谱可进一步细分为互不相交的四个组成部分,即四类点谱.针对3×3阶上三角算子矩阵,结合分析方法与算子分块技巧给出了四类点谱的可能谱.

According to the denseness and the closedness of range,the point spectrum of a bounded linear operator is split into four disjoint parts,i.e.,four classes of point spectra.For 3×3 upper triangular operator matrices,the possible point spectra■σ_p,(MD,E,F)(i=1,2,3,4)are D,E,F given by means of the analysis method and block operator technique.