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Related papers: Some weighted numerical radius inequalities

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We study the numerical range of bounded linear operators on quaternionic Hilbert spaces and its relation with the S-spectrum. The class of complex operators on quaternionic Hilbert spaces is introduced and the upper bild of normal complex…

Functional Analysis · Mathematics 2022-10-12 Luís Carvalho , Cristina Diogo , Sérgio Mendes

In this work, the mixed Schwarz inequality for semi-Hilbertian space operators is proved. Namely, for every positive Hilbert space operator $A$. If $f$ and $g$ are nonnegative continuous functions on $\left[0,\infty\right)$ satisfying…

Functional Analysis · Mathematics 2020-07-06 Mohammad W. Alomari

We develop upper and lower bounds for the numerical radius of $2\times 2$ off-diagonal operator matrices, which generalize and improve on the existing ones. We also show that if $A$ is a bounded linear operator on a complex Hilbert space…

Functional Analysis · Mathematics 2021-10-07 Pintu Bhunia , Kallol Paul

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…

Functional Analysis · Mathematics 2020-05-12 Kais Feki

The aim of the present article is to give an introduction to the concept of quasi-unitary equivalence and to define several (pseudo-)metrics on the space of self-adjoint operators acting possibly in different Hilbert spaces. As some of the…

Functional Analysis · Mathematics 2025-04-30 Olaf Post , Jan Simmer

New upper and lower bounds for the numerical radii of Hilbert space operators are given. Among our results, we prove that if $A\in \mathcal{B} \left( \mathcal{H}\right) $ is a hyponormal operator, then for all non-negative non-decreasing…

Functional Analysis · Mathematics 2018-01-11 H. R. Moradi , M. E. Omidvar , K. Shebrawi

We show that some previous results concerning the boundedness of differentiation and integration operators on weighted spaces given by radial weights in the unit disk or the complex plane might fail without some natural additional…

Functional Analysis · Mathematics 2016-04-04 Alexander V. Abanin , Pham Trong Tien

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…

Functional Analysis · Mathematics 2022-02-10 Anirban Sen , Pintu Bhunia , Kallol Paul

Let $\mathbb{A}= \begin{pmatrix} A & 0 \\ 0 & A \\ \end{pmatrix} $ be a $2\times2$ diagonal operator matrix whose each diagonal entry is a bounded positive (semidefinite) linear operator $A$ acting on a complex Hilbert space $\mathcal{H}$.…

Functional Analysis · Mathematics 2022-04-04 Kais Feki , Satyajit Sahoo

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 and prove some properties of $(\alpha;\beta)$-normal operators according to semi-Hilbertian space structures. Furthermore we s,ate various inequalities between the A-operator norm and A-numerical radius of…

Functional Analysis · Mathematics 2016-10-12 Abdelkader Benali , Ould Ahmed Mahmoud Sid Ahmed

In the context of variable exponent Lebesgue spaces equipped with a lower Ahlfors measure we obtain weighted norm inequalities over bounded domains for the centered fractional maximal function and the fractional integral operator.

Analysis of PDEs · Mathematics 2009-07-31 Osvaldo Gorosito , Gladis Pradolini , Oscar Salinas

In this paper we completely describe the numerical range of Toeplitz operators on weighted Bergman spaces with harmonic symbol. We also characterize the numerical range of weighted composition operators on weighted Bergman spaces and…

Functional Analysis · Mathematics 2025-02-06 Anirban Sen , Subhadip Halder , Riddhick Birbonshi , Kallol Paul

We present the weighted weak group inverse, which is a new generalized inverse of operators between two Hilbert spaces, introduced to extend weak group inverse for square matrices. Some characterizations and representations of the weighted…

Functional Analysis · Mathematics 2019-03-05 Dijana Mosic , Daochang Zhang

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

Functional Analysis · Mathematics 2020-04-01 Kais Feki

We consider the ratio of two Gauss hypergeometric functions, in which the parameters of the numerator function differ from the respective parameters of the denominator function by integers. We derive explicit integral representations for…

Classical Analysis and ODEs · Mathematics 2021-12-30 Alexander Dyachenko , Dmitrii Karp

In this paper, we investigate the spectral radius al- gebras related to the weighted conditional expectation operators on the Hilbert spaces L2(F). We give a large classes of operators on L2(F) that have the same spectral radius algebra. As…

Functional Analysis · Mathematics 2016-02-15 Yousef Estaremi , Mohammad Reza Jabbarzadeh

In this article, we explore the celebrated Gr\"{u}ss inequality, where we present a new approach using the Gr\"{u}ss inequality to obtain new refinements of operator means inequalities. We also present several operator Gr\"{u}ss-type…

Functional Analysis · Mathematics 2020-09-17 H. R. Moradi , S. Furuichi , Z. Heydarbeygi , M. Sababheh

We obtain several sharp lower and upper bounds for the Euclidean operator radius of a pair of bounded linear operators defined on a complex Hilbert space. As applications of these bounds we deduce a chain of new bounds for the classical…

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

In this paper, we show some refinements of generalized numerical radius inequalities involving the Young and Heinz inequalities. In particular, we present \begin{align*}…

Functional Analysis · Mathematics 2018-05-22 Monire Hajmohamadi , Rahmatollah Lashkaripour , Mojtaba Bakherad