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Related papers: Inequalities for the generalized numerical radius

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In this paper, we generalize the notions of numerical radius parallelism and numerical radius Birkhoff orthogonality, originally formulated for operators on Hilbert spaces, to operators on normed spaces. We then proceed to demonstrate their…

Functional Analysis · Mathematics 2024-12-03 Jiaye Bi , Huayou Xie , Yongjin Li

Suppose $A=[a_{ij}]\in \mathcal{M}_n(\mathbb{C})$ is a complex $n \times n$ matrix and $B\in \mathcal{B}(\mathcal{H})$ is a bounded linear operator on a complex Hilbert space $\mathcal{H}$. We show that $w(A\otimes B)\leq w(C),$ where…

Functional Analysis · Mathematics 2026-01-16 Pintu Bhunia , Sujit Sakharam Damase , Apoorva Khare

Let $A$ be a bounded linear operator defined on a complex Hilbert space and let $|A|=(A^*A)^{1/2}$ be the positive square root of $A$. Among other refinements of the well known numerical radius inequality $w^2(A)\leq \frac12 \|A^*A+AA^*\|$,…

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

Some of the important inequalities associated with quantum entropy are immediate algebraic consequences of the Hansen-Pedersen-Jensen inequality. A general argument is given using matrix perspectives of operator convex functions. A matrix…

Mathematical Physics · Physics 2009-11-13 Edward G. Effros

Some rearrangement inequalities for symmetric norms on matrices are given as well as related results for operator convex functions.

Functional Analysis · Mathematics 2007-05-23 Jean-Christophe Bourin

We present several matrix and operator inequalities of Hermite-Hadamard type. We first establish a majorization version for monotone convex functions on matrices. We then utilize the Mond-Pecaric method to get an operator version for convex…

Functional Analysis · Mathematics 2013-04-02 Mohammad Sal Moslehian

Recently, several authors have proved inequalities on the spectral radius $\rho$, operator norm $\|\cdot\|$ and numerical radius of Hadamard products and ordinary products of non-negative matrices that define operators on sequence spaces,…

Spectral Theory · Mathematics 2017-01-05 Aljoša Peperko

Using the polar decomposition of a bounded linear operator $A$ defined on a complex Hilbert space, we obtain several numerical radius inequalities of the operator $A$, which generalize and improve the earlier related ones. Among other…

Functional Analysis · Mathematics 2023-03-07 Pintu Bhunia

We prove numerical radius inequalities involving commutators of $G_{1}$ operators and certain analytic functions. Among other inequalities, it is shown that if $A$ and $X$ are bounded linear operators on a complex Hilbert space, then…

Functional Analysis · Mathematics 2017-09-07 Mojtaba Bakherad , Fuad Kittaneh

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…

Functional Analysis · Mathematics 2019-03-06 Catalin Badea , Michel Crouzeix , Hubert Klaja

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…

Functional Analysis · Mathematics 2022-11-02 Mohammad W. Alomari , Mohammad Sababheh , Cristian Conde , Hamid Reza Moradi

This article has two interpenetrating motifs. One is an exposition of some major ideas and techniques behind the use of block matrices, and especially their positivity properties. This is done by focussing on one major problem:…

Functional Analysis · Mathematics 2023-08-01 Rajendra Bhatia , Tanvi Jain

By the help of power series f we can naturally construct another power series that has as coefficients the absolute values of the coefficients of f. Utilising these functions we prove some inequalities for the spectral radius of the bounded…

Functional Analysis · Mathematics 2013-02-13 S. S. Dragomir

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…

Functional Analysis · Mathematics 2025-07-09 M. H. M. Rashid

In this work, we improve and refine some numerical radius inequalities. In particular, for all Hilbert space operators $T$, the celebrated Kittaneh inequality reads: \begin{align*} \frac{1}{4}\left\| T^*T + TT^*\right\|\le w^{2 }\left(T…

Functional Analysis · Mathematics 2019-12-04 Mohammad W. Alomari

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…

Functional Analysis · Mathematics 2026-03-05 Mehdi Naimi , Mohammed Benharrat , Faouzi Hireche

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…

Functional Analysis · Mathematics 2021-09-21 Kais Feki

The aim of this paper is to generalize the Hermite--Hadamard inequality for functions convex on the coordinates. Our composite result generalizes the result of Dragomir in \cite{Drag}. Many other interesting inequalities can be derived from…

Classical Analysis and ODEs · Mathematics 2018-01-01 Eze R. Nwaeze

We generalize von Neumann's well-known trace inequality, as well as related eigenvalue inequalities for hermitian matrices, to Schatten-class operators between complex Hilbert spaces of infinite dimension. To this end, we exploit some…

Functional Analysis · Mathematics 2023-03-30 Gunther Dirr , Frederik vom Ende

In this work, an extension of the generalized mixed Schwarz inequality is proved. A companion of the generalized mixed Schwarz inequality is established by merging both Cartesian and Polar decompositions of operators. Based on that some…

Functional Analysis · Mathematics 2018-11-06 Mohammad W. Alomari
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