论文标题
上三角的完成问题$ 3 \ times3 $任意Banach空间上的操作员矩阵
Completion problem of upper triangular $3\times3$ operator matrices on arbitrary Banach spaces
论文作者
论文摘要
我们解决了$ 3 \ times3 $上三角操作员矩阵的完成问题,该矩阵直接以Banach空间为单位,因此推广了Han,Lee,Lee,Lee的著名结果(Proc。Amer。Math。Soc。128(1)(2000),119-123,119-123),以更大的尺寸。我们的主要工具是Harte的索引定理和Banach空间嵌入的幽灵。我们通过利用内部常规操作员的分解特性以及需要在需要时利用分解特性来克服BANACH空间中缺乏正交性。最后,我们提供了一些必需结果,与$ n \ times n $上三角操作员的可逆性相关,$ n> 3 $。
We solve the completion problem of $3\times3$ upper triangular operator matrix acting on a direct sum of Banach spaces and hence generalize the famous result of Han, Lee, Lee (Proc. Amer. Math. Soc. 128 (1) (2000), 119-123) to a greater dimension of a matrix. Our main tools are Harte's ghost of an index theorem and Banach spaces embeddings. We overcome the lack of orthogonality in Banach spaces by exploiting decomposition properties of inner regular operators, and of Fredholm regular operators when needed. Finally, we provide some necessity results related to the invertibility of $n\times n$ upper triangular operators, $n>3$.