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相关论文: Refinements of Some Numerical radius inequalities …

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New inequalities for the numerical radius of bounded linear operators defined on a complex Hilbert space $\mathcal{H}$ are given. In particular, it is established that if $T$ is a bounded linear operator on a Hilbert space $\mathcal{H}$…

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

Operator matrices have played a significant role in studying Hilbert space operators. In this paper, we discuss further properties of operator matrices and present new estimates for the operator norms and numerical radii of such operators.…

泛函分析 · 数学 2022-06-28 Fuad Kittaneh , Hamid Reza Moradi , Mohammad Sababheh

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

The main aim of this article is to establish several $p$-numerical radius inequalities via the $(f,g)$-Aluthge transform of Hilbert space operators and operator matrices. Furthermore, various classical numerical radius and norm inequalities…

泛函分析 · 数学 2025-04-08 Satyajit Sahoo

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

In the present paper, we provide several inequalities for the generalized numerical radius of operator matrices as introduced by A. Abu-omar and F. Kittaneh in [3]. We generalize the convexity and the log-convexity results obtained by M.…

泛函分析 · 数学 2020-04-22 H. Abbas , S. Harb , H. Issa

This paper is a continuation of a recent work on a new norm, christened the $ (\alpha, \beta)$-norm, on the space of bounded linear operators on a Hilbert space. We obtain some upper bounds for the said norm of $n\times n$ operator…

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

We present some upper and lower bounds for the numerical radius of a bounded linear operator defined on complex Hilbert space, which improves on the existing upper and lower bounds. We also present an upper bound for the spectral radius of…

泛函分析 · 数学 2024-08-13 Pintu Bhunia , Santanu Bag , Kallol Paul

This article implements a simple convex approach and block techniques to obtain several new refined versions of numerical radius inequalities for Hilbert space operators. This includes comparisons among the norms of the operators, their…

泛函分析 · 数学 2023-02-15 Mohammad Sababheh , Cristian Conde , Hamid Reza Moradi

In this paper, we aim to establish a range of numerical radius inequalities. These discoveries will bring us to a recently validated numerical radius inequality and will present numerical radius inequalities that exhibit enhanced precision…

泛函分析 · 数学 2024-10-07 M. H. M. Rashid

In this paper, we achieve new and improved numerical radius inequalities of operators defined on a Hilbert space by using Orlicz function and Hermite-Hadamard inequality. The upper bounds of various inequalities involving numerical radii…

泛函分析 · 数学 2024-04-08 Amit Maji , Atanu Manna , Ram Mohapatra

In this paper, we present several new bounds for the norm and numerical radius of sums of Hilbert space operators. The obtained bounds form a new collection that enriches our understanding of these bounds. We compare our bounds with the…

泛函分析 · 数学 2026-02-17 Zameddin I. Ismailov , Pembe Ipek Al , Hamid Reza Moradi , Mohammad Sababheh

We completely characterize Birkhoff-James orthogonality with respect to numerical radius norm in the space of bounded linear operators on a complex Hilbert space. As applications of the results obtained, we estimate lower bounds of…

泛函分析 · 数学 2024-08-13 Arpita Mal , Kallol Paul , Jeet Sen

We present some new upper and lower bounds for the numerical radius of bounded linear operators on a complex Hilbert space and show that these are stronger than the existing ones. In particular, we prove that if $A$ is a bounded linear…

泛函分析 · 数学 2024-08-23 Pintu Bhunia , Suvendu Jana , Kallol Paul

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

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

In this article, we present some new inequalities for the numerical radius of products of Hilbert space operators and the generalized Aluthge transform. In particular, we show some upper bounds for $\omega(ABC+DEF)$ using the celebrated…

泛函分析 · 数学 2022-06-03 Mohammad Sababheh , Cristian Conde , Hamid Reza Moradi

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

This study presents new upper bounds for the numerical radii of operator matrices, with a focus on $n \times n$ and $2 \times 2$ block matrices acting on Hilbert space direct sums. By employing techniques such as the H\"older-McCarthy…

泛函分析 · 数学 2025-08-05 M. H. M. Rashid

This paper establishes several new inequalities for the $A$-norm and $A$-numerical radius of operator sums in semi-Hilbertian spaces, significantly advancing the existing theory. We present two fundamental refinements of the generalized…

泛函分析 · 数学 2025-07-09 M. H. M. Rashid