研究了无界上三角算子矩阵的可逆性问题,运用线性算子的近似零空间给出了无界上三角算子矩阵可逆的充分必要条件,运用近似零空间的概念给出了斜对角元有界非负Hamilton算子可逆的充分必要条件,进而推广了俄罗斯学者Kurina给出的对角元有界非负Hamilton算子可逆的充分条件。
The invertibility of unbounded upper triangular operator matrices is studied,and the necessary and sufficient conditions are obtained by applying the approximate null space.The necessary and sufficient conditions for the invertibility of the nonnegative Hamiltonian operator with bounded off-diagonal entries are obtained,which extend Kurina’s results.