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相关论文: On generalized Davis-Wielandt radius inequalities …

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We obtain upper and lower bounds for the Davis-Wielandt radius of bounded linear operators defined on a complex Hilbert space, which improve on the existing ones. We also obtain bounds for the Davis-Wielandt radius of operator matrices. We…

泛函分析 · 数学 2024-08-14 Pintu Bhunia , Aniket Bhanja , Santanu Bag , Kallol Paul

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

Let $\mathcal{H}$ be a complex Hilbert space and let $A$ be a positive operator on $\mathcal{H}$. We obtain new bounds for the $A$-numerical radius of operators in semi-Hilbertian space $\mathcal{B}_A(\mathcal{H})$ that generalize and…

泛函分析 · 数学 2024-08-14 Pintu Bhunia , Raj Kumar Nayak , Kallol Paul

In this work, some new upper and lower bounds of the Davis-Wielandt radius are introduced. Generalizations of some presented results are obtained. Some bounds of the Davis-Wielandt radius for $n\times n$ operator matrices are established.…

泛函分析 · 数学 2020-08-04 Mohammad W. Alomari

Let ($\mathcal{H}, \langle . , .\rangle )$ be a complex Hilbert space and $A$ be a positive bounded linear operator on it. Let $w_A(T)$ be the $A$-numerical radius and $\|T\|_A$ be the $A$-operator seminorm of an operator $T$ acting on the…

泛函分析 · 数学 2020-04-17 Nirmal Chandra Rout , Satyajit Sahoo , Debasisha Mishra

Let $A$ be a positive operator on a complex Hilbert space $\mathcal{H}.$ We present inequalities concerning upper and lower bounds for $A$-numerical radius of operators, which improve on and generalize the existing ones, studied recently in…

泛函分析 · 数学 2024-08-13 Pintu Bhunia , Kallol Paul , Raj Kumar Nayak

For a given bounded positive (semidefinite) linear operator $A$ on a complex Hilbert space $\big(\mathcal{H}, \langle \cdot\mid \cdot\rangle \big)$, we consider the semi-Hilbertian space $\big(\mathcal{H}, \langle \cdot\mid \cdot\rangle_A…

泛函分析 · 数学 2020-05-13 Kais Feki

This paper presents a study of the generalized Davis-Wielandt radius of Hilbert space operators. New lower bounds for the generalized Davis-Wielandt radius and numerical radius are provided. An alternative of the triangular inequality for…

泛函分析 · 数学 2026-03-05 Mehdi Naimi , Mohammed Benharrat , Faouzi Hireche

We present sharp lower bounds for the A-numerical radius of semi-Hilbertian space operators. We also present an upper bound. Further we compute new upper bounds for the $B$-numerical radius of $2 \times 2$ operator matrices where $B =…

泛函分析 · 数学 2020-04-22 Pintu Bhunia , Raj Kumar Nayak , Kallol Paul

Consider a complex Hilbert space $\left(\mathcal{H}, \langle \cdot, \cdot \rangle\right)$ equipped with a positive bounded linear operator $A$ on $\mathcal{H}$. This induces a semi-norm $\|\cdot\|_A$ through the semi-inner product $\langle…

泛函分析 · 数学 2025-07-09 M. H. M. Rashid

Let $\mathbb{A}=\left( \begin{array}{cc} A & 0 \\ 0 & A \\ \end{array} \right)$ be the $2\times2$ diagonal operator matrix determined by a positive bounded operator $A$. For semi-Hilbertian operators $X$ and $Y$, we first show that…

泛函分析 · 数学 2020-05-12 Qingxiang Xu , Zhongming Ye , Ali Zamani

Let $\big(\mathcal{H}, \langle \cdot\mid \cdot\rangle \big)$ be a complex Hilbert space and $A$ be a positive (semidefinite) bounded linear operator on $\mathcal{H}$. The semi-inner product induced by $A$ is given by ${\langle x\mid…

泛函分析 · 数学 2020-05-12 Kais Feki

In this paper we generalize the concept of Davis-Wielandt shell of operators on a Hilbert space when a semi-inner product induced by a positive operator $A$ is considered. Moreover, we investigate the parallelism of $A$-bounded operators…

泛函分析 · 数学 2019-12-10 Kais Feki , Sid Ahmed Ould Ahmed Mahmoud

We develope new lower bounds for the $A$-numerical radius of semi-Hilbertian space operators, and applying these bounds we obtain upper bounds for the $A$-numerical radius of the commutators of operators. The bounds obtained here improve on…

泛函分析 · 数学 2024-08-14 Pintu Bhunia , Kallol Paul

Let $A$ be a positive bounded linear operator acting on a complex Hilbert space $\big(\mathcal{H}, \langle \cdot\mid \cdot\rangle \big)$. Let $\omega_A(T)$ and ${\|T\|}_A$ denote the $A$-numerical radius and the $A$-operator seminorm of an…

泛函分析 · 数学 2020-04-20 Kais Feki

We give new inequalities for $A$-operator seminorm and $A$-numerical radius of semi-Hilbertian space operators and show that the inequalities obtained here generalize and improve on the existing ones. Considering a complex Hilbert space…

泛函分析 · 数学 2024-08-14 Pintu Bhunia , Kallol Paul , Raj Kumar Nayak

In this paper, we introduce a new semi-norm of operators on a semi-Hilbertian space, which generalizes the A-numerical radius and A-operator semi-norm. We study the basic properties of this semi-norm, including upper and lower bounds for…

泛函分析 · 数学 2024-08-14 Pintu Bhunia , Anirban Sen , Kallol Paul

We introduce a new norm on the space of bounded linear operators on a complex Hilbert space, which generalizes the numerical radius norm, the usual operator norm and the modified Davis-Wielandt radius. We study basic properties of this…

泛函分析 · 数学 2024-08-14 D. Sain , P. Bhunia , A. Bhanja , K. Paul

Let $A$ be a positive bounded operator on a Hilbert space $\big(\mathcal{H}, \langle \cdot, \cdot\rangle \big)$. The semi-inner product ${\langle x, y\rangle}_A := \langle Ax, y\rangle$, $x, y\in\mathcal{H},$ induces a seminorm…

泛函分析 · 数学 2021-07-23 M. S. Moslehian , Q. Xu , A. Zamani

Several upper and lower bounds of the Davis-Wielandt-Berezin radius of bounded linear operators defined on a reproducing kernel Hilbert space are given. Further, an inequality involving the Berezin number and the Davis-Wielandt-Berezin…

泛函分析 · 数学 2022-02-10 Anirban Sen , Pintu Bhunia , Kallol Paul
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