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相关论文: On the estimation of the $q$-numerical radius via …

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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, the $q$-numerical radius of operators in semi-Hilbertian spaces is studied. New characterizations are established, and sharp upper and lower bounds for the $q$-numerical radius are derived. Moreover, several inequalities…

泛函分析 · 数学 2026-03-19 Jyoti Rani

In this paper, several significant upper bounds for the numerical radius and $a$-numerical radius of an element in a $\mathcal{C}^*$-algebra are obtained using Orlicz functions. Many well-known results are obtained from our findings,…

算子代数 · 数学 2024-11-08 Saikat Mahapatra , Riddhick Birbonshi , Arnab Patra

Employing the Orlicz functions we extend the Buzano's inequality which is a refinement of the Cauchy-Schwarz inequality. Also using the Orlicz functions we obtain several numerical radius inequalities for a bounded linear operator as well…

泛函分析 · 数学 2024-08-26 Pintu Bhunia , Raj Kumar Nayak

This article introduces several new upper bounds for the $q$-numerical radius of bounded linear operators on complex Hilbert spaces. Our results refine some of the existing upper bounds in this field. The $q$-numerical radius inequalities…

泛函分析 · 数学 2023-06-08 Arnab Patra , Falguni Roy

In this article, we developed a series of new inequalities involving the $q$-numerical radius for operators and $2\times 2$ operator matrices. These inequalities serve to establish both lower and upper bounds for the $q$-numerical radius of…

泛函分析 · 数学 2025-02-07 Satyajit Sahoo , Nirmal Chandra Rout

In this paper, we show several bounds for the numerical radius of a Hilbert space operator in terms of the Euclidean operator norm. The obtained forms will enable us to find interesting refinements of celebrated results in the literature.…

泛函分析 · 数学 2023-09-21 Mohammad Sababheh , Hamid Reza Moradi , Mohammad Alomari

We obtain upper bounds for the numerical radius of a product of Hilbert space operators which improve on the existing upper bounds. We generalize the numerical radius inequalities of $n\times n$ operator matrices by using non-negative…

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

This paper introduces and investigates the concept of the $q$-numerical range for tuples of bounded linear operators in Hilbert spaces. We establish various inequalities concerning the $q$-numerical radius associated with these operator…

泛函分析 · 数学 2024-10-08 Kais Feki , Arnab Patra , Jyoti Rani , Zakaria Taki

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

In this study, the classical results on the joint numerical radius for $n$-tuples of Hilbert space operators are extended to the setting of the joint $(f,\delta)$-numerical radius. New and diverse contributions to this area are provided,…

泛函分析 · 数学 2026-03-20 Zameddin I. Ismailov , Sergei Silvestrov , Pembe Ipek Al

We give an expression for a generalized numerical radius of Hilbert space operators and then apply it to obtain upper and lower bounds for the generalized numerical radius. We also establish some generalized numerical radius inequalities…

泛函分析 · 数学 2019-09-26 A. Zamani , M. S. Moslehian , Q. Xu , C. Fu

We establish new integral inequalities for the numerical radius and the operator norm of bounded linear operators on Hilbert spaces. Our results refine classical triangle-type and operator matrix inequalities by incorporating convex…

泛函分析 · 数学 2026-02-17 Shiva Sheybani , 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 obtain new lower and upper bounds for the numerical radius of a bounded linear operator $A$ on a complex Hilbert space, which refine the existing ones. In particular, if $w(A)$ and $\|A\|$ denote the numerical radius and operator norm of…

泛函分析 · 数学 2026-03-05 Pintu Bhunia , Rukaya Majeed

In this article, we obtain several new weighted bounds for the numerical radius of a Hilbert space operator. The significance of the obtained results is the way they generalize many existing results in the literature; where certain values…

泛函分析 · 数学 2021-03-09 Shiva Sheybani , Mohammed Sababheh , Hamid Reza Moradi

This paper investigates new properties of $q$-numerical ranges for compact normal operators and establishes refined upper bounds for the $q$-numerical radius of Hilbert space operators. We first prove that for a compact normal operator $T$…

泛函分析 · 数学 2025-12-17 Mohammad H. M. Rashid

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

In this paper, we begin by showing a new generalization of the celebrated Cauchy-Schwarz inequality for the inner product. Then, this generalization is used to present some bounds for the Euclidean operator radius and the Euclidean operator…

泛函分析 · 数学 2023-10-09 Mohammad Sababheh , Hamid Reza Moradi

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
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