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Related papers: Some Numerical radius inequalities

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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…

Functional Analysis · Mathematics 2024-08-13 Pintu Bhunia , Kallol Paul , Raj Kumar Nayak

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…

Functional Analysis · Mathematics 2024-08-13 Pintu Bhunia , Santanu Bag , Kallol Paul

Some elementary inequalities providing upper bounds for the difference of the norm and the numerical radius of a bounded linear operator on Hilbert spaces under appropriate conditions are given.

Functional Analysis · Mathematics 2007-05-23 Sever Silvestru Dragomir

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…

Functional Analysis · Mathematics 2024-08-14 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…

Functional Analysis · Mathematics 2024-08-14 Pintu Bhunia , Raj Kumar Nayak , Kallol Paul

In this article, we present some new general forms of numerical radius inequalities for Hilbert space operators. The significance of these inequalities follow from the way they extend and refine some known results in this field. Among other…

Functional Analysis · Mathematics 2019-06-21 Mohammad Sababheh , Hamid Reza Moradi

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…

Functional Analysis · Mathematics 2023-06-08 Arnab Patra , Falguni Roy

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…

Functional Analysis · Mathematics 2019-09-26 A. Zamani , M. S. Moslehian , Q. Xu , C. Fu

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 =…

Functional Analysis · Mathematics 2020-04-22 Pintu Bhunia , Raj Kumar Nayak , Kallol Paul

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…

Functional Analysis · Mathematics 2024-08-13 Pintu Bhunia , Kallol Paul

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 $\mathcal{H}$…

Functional Analysis · Mathematics 2024-08-14 Pintu Bhunia , Kallol Paul

In this work, some generalizations and refinements inequalities for numerical radius of the product of Hilbert space operators are proved. New inequalities for numerical radius of block matrices of Hilbert space operators are also…

Functional Analysis · Mathematics 2019-03-18 Mohammad W. Alomari

Some new inequalities for the norm and the numerical radius of composite operators generated by a pair of operators are given.

Functional Analysis · Mathematics 2007-05-23 Sever Silvestru Dragomir

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…

Functional Analysis · Mathematics 2024-08-14 Pintu Bhunia , Kallol Paul , Raj Kumar Nayak

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…

Functional Analysis · Mathematics 2024-08-23 Pintu Bhunia , Suvendu Jana , Kallol Paul

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…

Functional Analysis · Mathematics 2020-04-17 Nirmal Chandra Rout , Satyajit Sahoo , Debasisha Mishra

New inequalities for the $A$-numerical radius of the products and sums of operators acting on a semi-Hilbert space, i.e. a space generated by a positive semidefinite operator $A$, are established. In particular, it is proved for operators…

Functional Analysis · Mathematics 2020-12-23 Pintu Bhunia , Kais Feki , Kallol Paul

In this work, an improvement of H\"{o}lder-McCarty inequality is established. Based on that, several refinements of the generalized mixed Schwarz inequality are obtained. Consequently, some new numerical radius inequalities are proved. New…

Functional Analysis · Mathematics 2019-03-06 Mohammad W. Alomari

We prove several numerical radius inequalities for linear operators in Hilbert spaces. It is shown, among other inequalities, that if $A$ is a bounded linear operator on a complex Hilbert space, then \[\omega \left( A \right)\le…

Functional Analysis · Mathematics 2021-06-15 Farzaneh Pouladi Najafabadi , Hamid Reza Moradi

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…

Functional Analysis · Mathematics 2021-03-09 Shiva Sheybani , Mohammed Sababheh , Hamid Reza Moradi
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