论文标题

一些$ \ mathbb {a} $ - $ d \ times d $ operator矩阵的数值半径不平等

Some $\mathbb{A}$-numerical radius inequalities for $d\times d$ operator matrices

论文作者

Feki, Kais

论文摘要

令$ a $为积极的(半限制)有限的线性运算符,作用于复杂的Hilbert Space $ \ big(\ Mathcal {h},\ langle \ cdot \ cdot \ cdot \ cdot \ cdot \ rangle \ big)$。半inner产品$ {\ langle x \ mid y \ rangle} _a:= \ langle ax \ mid y \ rangle $,$ x,y \ in \ mathcal {h h} $诱导eminorm $ {\ | \ cdot \ | \ cdot \ |} _a $ on $ n $ \ nmathcal of seminorm $ {令$ t $为$ \ natercal {h} $上的$ a $ and-bound运算符,$ a $ a-numerical radius的$ t $ of $ t $由\ begin {align*}ω___________________________________________________________________________________部门(t)= \ sup \ big \ big \ big \ big | \ Mathcal {h},\,{\ | x \ |} _a = 1 \ big \}。 \ end {align*}在本文中,我们为$ω__\ mathbb {a}(\ Mathbb {t})$建立了几个不等式,其中$ \ mathbb {t} =(t_ {ij {ij})$是$ d \ times d \ times d \ times d \ times d $ d $ operrix with $ t_ $ t_ $ a $ a $ a $ a $ a a $ a a $ a $ \ mathbb {a} $是对角线运算符矩阵,其每个对角线条目为$ a $。

Let $A$ be a positive (semidefinite) bounded linear operator acting on a complex Hilbert space $\big(\mathcal{H}, \langle \cdot\mid \cdot\rangle \big)$. The semi-inner product ${\langle x\mid y\rangle}_A := \langle Ax\mid y\rangle$, $x, y\in\mathcal{H}$ induces a seminorm ${\|\cdot\|}_A$ on $\mathcal{H}$. Let $T$ be an $A$-bounded operator on $\mathcal{H}$, the $A$-numerical radius of $T$ is given by \begin{align*} ω_A(T) = \sup\Big\{\big|{\langle Tx\mid x\rangle}_A\big|: \,\,x\in \mathcal{H}, \,{\|x\|}_A = 1\Big\}. \end{align*} In this paper, we establish several inequalities for $ω_\mathbb{A}(\mathbb{T})$, where $\mathbb{T}=(T_{ij})$ is a $d\times d$ operator matrix with $T_{ij}$ are $A$-bounded operators and $\mathbb{A}$ is the diagonal operator matrix whose each diagonal entry is $A$.

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