论文标题
封闭式正态操作员及其产品
Closed-range posinormal operators and their products
论文作者
论文摘要
我们专注于两个问题，即何时两个正态操作员的乘积是sustormoral的问题，给出了（1）层伸正常操作员具有封闭范围的必要条件和足够条件，以及（2）通勤封闭范围的正态运算符的足够条件，使其具有封闭范围的正效率。我们还讨论了正态运算符和EP运营商（以及低调操作员）之间的关系，并以Harartwig-Katz定理的新证明结论，该证明是何时$ \ cc^n $上的正态操作员的乘积是正态的。
We focus on two problems relating to the question of when the product of two posinormal operators is posinormal, giving (1) necessary conditions and sufficient conditions for posinormal operators to have closed range, and (2) sufficient conditions for the product of commuting closed-range posinormal operators to be posinormal with closed range. We also discuss the relationship between posinormal operators and EP operators (as well as hypo-EP operators), concluding with a new proof of the Hartwig-Katz Theorem, which characterizes when the product of posinormal operators on $\CC^n$ is posinormal.
