论文标题

C* - 模块运算符,在广义的cauchy--schwarz类型不平等中满足

C*-module operators which satisfy in the generalized Cauchy--Schwarz type inequality

论文作者

Zamani, Ali

论文摘要

令$ \ Mathcal {l}(\ Mathscr {h})$表示$ C^*$ - 在Hilbert $ c^*$ - Module $ \ Mathscr {h h} $上的可伴随运算符的代数。我们在$ \ Mathcal {l}(\ Mathscr {h})$中介绍了对运营商的广义cauchy-schwarz $,并研究了操作员的各种属性,这些属性满足了概述的cauchy-schwarz不平等。特别是,我们证明,如果运算符$ a \ in \ mathcal {l}(\ mathscr {h})$满足了概括的cauchy-schwarz不平等,使$ a $ a $具有极地分解,那么$ a $ a $是超凡的。此外,我们表明,如果对于$ a $,平等在广义的Cauchy-Schwarz不平等中都有,那么$ a $是同伴。除其他事项外,当$ a $具有极地分解时,我们证明$ a $是半高调的,并且仅当$ \ big \ | \ | \ langle ax,y \ rangle \ big \ | \ leq \ big \ | {| a |}^{1/2} x \ big \ | | \ big \ | {| a | a |}^{1/2} y \ big \ | $ for ALL $ x,y \ in \ MATHSCR {H} $。

Let $\mathcal{L}(\mathscr{H})$ denote the $C^*$-algebra of adjointable operators on a Hilbert $C^*$-module $\mathscr{H}$. We introduce the generalized Cauchy-Schwarz inequality for operators in $\mathcal{L}(\mathscr{H})$ and investigate various properties of operators which satisfy the generalized Cauchy--Schwarz inequality. In particular, we prove that if an operator $A\in\mathcal{L}(\mathscr{H})$ satisfies the generalized Cauchy-Schwarz inequality such that $A$ has the polar decomposition, then $A$ is paranormal. In addition, we show that if for $A$ the equality holds in the generalized Cauchy-Schwarz inequality, then $A$ is cohyponormal. Among other things, when $A$ has the polar decomposition, we prove that $A$ is semi-hyponormal if and only if $\big\|\langle Ax, y\rangle\big\| \leq \big\|{|A|}^{1/2}x\big\|\big\|{|A|}^{1/2}y\big\|$ for all $x, y \in\mathscr{H}$.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源