POSITIVITY OF 2 x 2 BLOCK MATRICES OF OPERATORS
POSITIVITY OF 2 x 2 BLOCK MATRICES OF OPERATORS
复制标题
DOI:
10.1215/17358787-2019-0019
复制
发表时间:
2019-07-01
影响因子:
1.2
通讯作者:
Xu, Qingxiang
中科院分区:
文献类型:
--
作者:
Moslehian, Mohammad Sal;Kian, Mohsen;Xu, Qingxiang
We review some significant generalizations and applications of the celebrated Douglas theorem on equivalence of factorization, range inclusion, and majorization of operators. We then apply it to find a characterization of the positivity of 2 x 2 block matrices of operators on Hilbert spaces. Finally, we describe the nature of such block matrices and provide several ways for showing their positivity.