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相关论文: Bounds of numerical radius of bounded linear opera…

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Let $A$ be a positive (semidefinite) operator on a complex Hilbert space $\mathcal{H}$ and let $\mathbb{A}=\left(\begin{array}{cc} A & O O & A \end{array}\right).$ We obtain upper and lower bounds for the $A$-Davis-Wielandt radius of…

泛函分析 · 数学 2020-06-11 Aniket Bhanja , Pintu Bhunia , Kallol Paul

In this paper, we establish sharp bounds for the multilinear Hausdorff operators on mixed radial-angular local Morrey-type spaces, and we also give ralated applications of these operators. Meanwhile, sharp bounds for the multilinear…

泛函分析 · 数学 2025-10-01 Ronghui Liu , Qi Zhang

We study different operator radii of homomorphisms from an operator algebra into $B(H)$ and show that these can be computed explicitly in terms of the usual norm. As an application, we show that if $\Omega$ is a $K$-spectral set for a…

泛函分析 · 数学 2019-03-06 Catalin Badea , Michel Crouzeix , Hubert Klaja

This paper explores refinements of some operator norm inequalities through the generalized spherical Aluthge transform and the spherical Heinz transform. We introduce the spherical Schatten $p$-norm for operator tuples and establish several…

泛函分析 · 数学 2025-04-01 Fuad Kittaneh , Satyajit Sahoo , Hranislav Stanković

We revisit and extend known bounds on operator-valued functions of the type $$ T_1^{-z} S T_2^{-1+z}, \quad z \in \ol \Sigma = \{z\in\bbC\,|\, \Re(z) \in [0,1]\}, $$ under various hypotheses on the linear operators $S$ and $T_j$, $j=1,2$.…

泛函分析 · 数学 2014-05-08 Fritz Gesztesy , Yuri Latushkin , Fedor Sukochev , Yuri Tomilov

The numerical radius of a matrix is a scalar quantity that has many applications in the study of matrix analysis. Due to the difficulty in computing the numerical radius, inequalities bounding it have received a considerable attention in…

泛函分析 · 数学 2020-07-20 Yassine Bedrani , Fuad Kittaneh , Mohammed Sababheh

Given a bounded linear operator $T$ on separable Hilbert space, we develop an approach allowing one to construct a matrix representation for $T$ having certain specified algebraic or asymptotic structure. We obtain matrix representations…

泛函分析 · 数学 2020-10-20 Vladimir Müller , Yuri Tomilov

In this paper, we present intriguing findings that characterize both the closed (unbounded) and bounded EP operators on Hilbert spaces. Additionally, we demonstrate the result $\gamma(T) \leq r(T)$, where $T$ is a bounded EP operator, and…

泛函分析 · 数学 2024-12-10 Arup Majumdar , P. Sam Johnson

Let $A$ be a positive bounded linear operator on a complex Hilbert space $\mathcal{H}$ and $\mathcal{B}_{A}(\mathcal{H})$ be the subspace of all operators which admit $A$-adjoints operators. In this paper, we establish some inequalities…

泛函分析 · 数学 2021-09-21 Kais Feki

We study a generalized spherical means operator, viz. generalized spherical mean Radon transform, acting on radial functions. As the main results, we find conditions for the associated maximal operator and its local variant to be bounded on…

经典分析与常微分方程 · 数学 2020-10-22 Óscar Ciaurri , Adam Nowak , Luz Roncal

In this article, a series of new inequalities involving the $q$-numerical radius for $n\times n$ tridiagonal, and anti-tridiagonal operator matrices has been established. These inequalities serve to establish both lower and upper bounds for…

泛函分析 · 数学 2025-01-14 Satyajit Sahoo , Narayan Behera

This paper studies the diameter of the numerical range of bounded operators on Hilbert space and the induced seminorm, called the numerical diameter, on bounded linear maps between operator systems which is sensible in the case of unital…

泛函分析 · 数学 2024-07-03 Niel de Beaudrap , Christopher Ramsey

In this paper, we define a new concept of numerical range $W_{o}(\cdot)$ and prove its basic results. We also define the numerical radius $\omega_{o}(\cdot)$ and prove that $$\omega_{o}(T)\leq||| T|||\leq 2\omega_{o}(T).$$

算子代数 · 数学 2018-11-05 Marzieh Mehrazin , Maryam Amyari , Mohsen Erfanian Omidvar

In this paper we explore the properties of a bounded linear operator defined on a Banach space, in light of operator norm attainment. Using Birkhoff-James orthogonality techniques, we give a necessary condition for a bounded linear operator…

泛函分析 · 数学 2016-08-03 Debmalya Sain

In this work, some non smooth bilinear analogues of linear Littlewood-Paley square functions on the real line are studied. These bilinear operators are closely related to the bilinear Hilbert transforms and vector valued version of these…

泛函分析 · 数学 2008-11-19 Frederic Bernicot

Consider $\mathcal{H}$ is a complex Hilbert space and $A$ is a positive operator on $\mathcal{H}.$ The mapping $\langle\cdot,\cdot\rangle_A: \mathcal{H}\times \mathcal{H} \to \mathbb {C}$, defined as $\left\langle…

泛函分析 · 数学 2024-08-01 Messaoud Guesba , Somdatta Barik , Pintu Bhunia , Kallol Paul

The paper considers some new properties of the so-called $A$-maximal numerical range of operators, denoted by $W_{\max}^A(\cdot)$, where $A$ is a positive bounded linear operator acting on a complex Hilbert space $\mathcal{H}$. Some…

泛函分析 · 数学 2023-02-02 Abderrahim Baghdad , El Hassan Benabdi , Kais Feki

In this paper, by introducing some parameters, we define and study certain $p$-adic Hardy-Littlewood-P\'{o}lya-type integral operators acting on $p$-adic weighted Lebesgue spaces. We completely characterize $L^{q}-L^{r}$ boundedness of…

泛函分析 · 数学 2025-11-21 Jianjun Jin , Huabing Li

We completely characterize the boundedness of the area operators from the Bergman spaces $A^p_\alpha(\mathbb{B}_ n)$ to the Lebesgue spaces $L^q(\mathbb{S}_ n)$ for all $0<p,q<\infty$. For the case $n=1$, some partial results were…

复变函数 · 数学 2021-03-05 Xiaofen Lv , Jordi Pau , Maofa Wang

In this paper, we introduce the $f-$operator radius of Hilbert space operators as a generalization of the Euclidean operator radius and the $q-$operator radius. Properties of the newly defined radius are discussed, emphasizing how it…

泛函分析 · 数学 2022-11-02 Mohammad W. Alomari , Mohammad Sababheh , Cristian Conde , Hamid Reza Moradi