首页 | 本学科首页   官方微博 | 高级检索  
     检索      


On the Range of the Aluthge Transform
Authors:Guoxing Ji  Yongfeng Pang  Ze Li
Institution:(1) College of Mathematics and Information Science, Shaanxi Normal University, Xian, 710062, People’s Republic of China
Abstract:Let $$\mathcal{B}{\left( \mathcal{H} \right)}$$ be the algebra of all bounded linear operators on a complex separable Hilbert space $$\mathcal{H}{\text{.}}$$ For an operator $$T \in \mathcal{B}{\left( \mathcal{H} \right)}{\text{,}}$$ let $$ \ifmmode\expandafter\tilde\else\expandafter\~\fi{T} = |T|^{{\frac{1}{2}}} U|T|^{{\frac{1}{2}}}$$ be the Aluthge transform of T and we define $$\Delta {\left( T \right)} = \ifmmode\expandafter\tilde\else\expandafter\~\fi{T} $$ for all $$ \in \mathcal{B}{\left( \mathcal{H} \right)},$$ where T = U|T| is a polar decomposition of T. In this short note, we consider an elementary property of the range $$ R{\left( \Delta \right)} = {\left\{ { \ifmmode\expandafter\tilde\else\expandafter\~\fi{T}:T \in \mathcal{B}{\left( \mathcal{H} \right)}} \right\}} $$ of Δ. We prove that R(Δ) is neither closed nor dense in $$\mathcal{B}{\left( \mathcal{H} \right)}.$$ However R(Δ) is strongly dense if $$\mathcal{H}$$ is infinite dimensional. An erratum to this article is available at .
Keywords:Primary 47A15  Secondary 47B20
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号