基于算子扰动理论,研究了一类无界2×2上三角算子矩阵的谱,并得到其谱可由对角块刻画的若干充分条件.最后,举例说明结果的合理性.
Base on the theory of spectral perturbation,the spectrum of unbounded 2×2 upper triangular operator matrices is investigated.It is shown that under some assumptions,their spectrum can be determined by the diagonal elements.Moreover,some examples are presented to illustrate our results.