Results 51 to 60 of about 100,420 (296)
ON NUMERICAL RADIUS INEQUALITIES FOR OPERATOR PRODUCTS IN HILBERT SPACES
Проблемы анализаWe establish several numerical radius inequalities for products of two operators on a Hilbert space. Some of the obtained inequalities improve well-known results. More precisely, we show that if 𝐴, 𝐵 \in 𝐵(𝐻) double commute, then 𝑤(𝐴𝐵)
Ahmed Elbarbouchi +1 more
doaj +1 more source
Matricial Radius: A Relation of Numerical radius with Matricial Range
, 2019 It has been shown that if $T$ is a complex matrix, then {\small\begin{align*} ω(T)&=\frac{1}{n}\sup\left\{|\mathrm{Tr}\ X|;\ X\in W^n(T)\right\}\\ &=\frac{1}{n}\sup\left\{\|X\|_1;\ X\in W^n(T)\right\}\\ &= \sup\left\{ ω(X);\ X\in W^n(T)\right\} \end{align*} } where $n$ is a positive integer, $ω(T)$ is the numerical radius and $W^n(T)$ is ...
Dehghani, Mahdi +2 more
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Numerical radius in Hilbert C✻-modules [PDF]
Mathematical Inequalities & Applications, 2021 Utilizing the linking algebra of a Hilbert $C^*$-module $\big(\mathscr{V}, {\|\!\cdot\!\|}\big)$, we introduce $Ω(x)$ as a definition of numerical radius for an element $x\in\mathscr{V}$ and then show that $Ω(\cdot)$ is a norm on $\mathscr{V}$ such that $\frac{1}{2}{\|x\|} \leq Ω(x) \leq {\|x\|}$. In addition, we obtain an equivalent condition for $Ω(x)
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Some inequalities for the Euclidean operator radius of two operators in Hilbert spaces
, 2006 Some sharp bounds for the Euclidean operator radius of two bounded linear operators in Hilbert spaces are given. Their connection with Kittaneh’s recent results which provide sharp upper and lower bounds for the numerical radius of linear operators are ...
Dragomir, Sever S., Dragomir, Sever S
core +1 more source
Improved Bounds for the Euclidean Numerical Radius of Operator Pairs in Hilbert Spaces
MathematicsThis paper presents new lower and upper bounds for the Euclidean numerical radius of operator pairs in Hilbert spaces, demonstrating improvements over recent results by other authors.
Najla Altwaijry +2 more
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Applied Sciences, 2023 Compared with straight tunnels, small-radius curved tunnels are more common and have more complex influencing factors in urban underground traffic. Therefore, the seismic evaluation of small-radius curved tunnels is of great significance for the safe ...
Xiaojiu Feng +3 more
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The weighted Hilbert–Schmidt numerical radius
Linear Algebra and its Applications, 2023 Let $\mathbb{B}(\mathcal{H})$ be the algebra of all bounded linear operators on a Hilbert space $\mathcal{H}$ and let $N(\cdot)$ be a norm on $\mathbb{B}(\mathcal{H})$. For every $0\leq ν\leq 1$, we introduce the $w_{_{(N,ν)}}(A)$ as an extension of the classical numerical radius by \begin{align*} w_{_{(N,ν)}}(A):= \displaystyle{\sup_{θ\in \mathbb{R}}}
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Denseness of Numerical Radius Attaining Holomorphic Functions
Journal of Inequalities and Applications, 2009 We study the density of numerical radius attaining holomorphic functions on certain Banach spaces using the Lindenstrauss method. In particular, it is shown that if a complex Banach space X is locally uniformly convex, then the set of all numerical ...
Han Ju Lee
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Generalized Cauchy–Schwarz Inequalities and A-Numerical Radius Applications
Axioms, 2023 The purpose of this research paper is to introduce new Cauchy–Schwarz inequalities that are valid in semi-Hilbert spaces, which are generalizations of Hilbert spaces.
Najla Altwaijry +2 more
doaj +1 more source
Therapeutic Apheresis and Dialysis, EarlyView.ABSTRACT Introduction This study investigated the safety and efficacy of single‐needle Rheocarna therapy for chronic limb‐threatening ischemia (CLTI) with wounds. Methods Six patients with CLTI involving ulcers unresponsive to revascularization underwent single‐needle Rheocarna treatment.
Yasutaka Yamauchi +9 more
wiley +1 more source