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Related papers: Inequalities for the generalized numerical radius

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In this paper, a generalized Cauchy-Schwarz inequality for positive sesquilinear maps with values in noncommutative Lp-spaces for p > 1 are obtained. Bound estimates for their real and imaginary parts are also provided, and, as an…

Operator Algebras · Mathematics 2026-02-13 Giorgia Bellomonte , Stefan Ivkovic , Camillo Trapani

We obtain various upper bounds for the numerical radius $w(T)$ of a bounded linear operator $T$ defined on a complex Hilbert space $\mathcal{H}$, by developing the upper bounds for the $\alpha$-norm of $T$, which is defined as…

Functional Analysis · Mathematics 2023-01-11 Pintu Bhunia

A generalised trapezoid inequality for convex functions and applications for quadrature rules are given. A refinement and a counterpart result for the Hermite-Hadamard inequalities are obtained and some inequalities for pdf's and…

Numerical Analysis · Mathematics 2025-10-20 Sever Silvestru Dragomir

Mercer inequality for convex functions is a variant of Jensen's inequality, with an operator version that is still valid without operator convexity. This paper is two folded. First, we present a Mercer-type inequality for operators without…

Functional Analysis · Mathematics 2020-03-06 H. R. Moradi , S. Furuichi , M. Sababheh

Several refinements of norm and numerical radius inequalities of bounded linear operators on a complex Hilbert space are given. In particular, we show that if $A$ is a bounded linear operator on a complex Hilbert space, then $$…

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

This article focuses on several significant bounds of $q$-numerical radius $w_q(A)$ for sectorial matrix $A$ which refine and generalize previously established bounds. One of the significant bounds we have derived is as follows:…

Functional Analysis · Mathematics 2026-02-04 Jyoti Rani , Arnab Patra

Several matrix/operator inequalies are given. Most of them are unexpected extensions of the Araki Log-majorization theorem, obtained thanks to a new log-majorization for positive linear maps and normal operators (Theorem 2.9). The main idea…

Functional Analysis · Mathematics 2016-06-14 Jean-Christophe Bourin , Eun-Young Lee

The two well-known numerical radius inequalities for the tensor product $A \otimes B$ acting on $\mathbb{H} \otimes \mathbb{K}$, where $A$ and $B$ are bounded linear operators defined on complex Hilbert spaces $\mathbb{H} $ and $…

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

In this article, we present several inequalities treating operator means and the Cauchy-Schwarz inequality. In particular, we present some new comparisons between operator Heron and Heinz means, several generalizations of the difference…

Functional Analysis · Mathematics 2021-07-23 Y. Kapil , C. Conde , M. S. Moslehian , M. Singh , M. Sababheh

In this paper, we establish various inequalities for some differentiable mappings that are linked with the illustrious Hermite-Hadamard integral inequality for mappings whose derivatives are $s$-$(\alpha,m)$-convex.The generalised integral…

Functional Analysis · Mathematics 2013-04-10 Muhammad Muddassar , Muhammad Iqbal Bhatti , Wajeeha Irshad

In this article we study the generalized Hilbert matrix operator $\Gamma_\mu$ acting on the Bergman spaces $A^p$ of the unit disc for $1\leq p<\infty$. In particular, we characterize the measures $\mu$ for which the operator $\Gamma_\mu$ is…

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

Functional Analysis · Mathematics 2021-07-23 M. S. Moslehian , Q. Xu , A. Zamani

We review some convexity inequalities for Hermitian matrices an add one more to the list.

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

In this paper we give several expressions of spectral radius of a bounded operator on a Hilbert space, in terms of iterates of Aluthge transformation, numerical radius and the asymptotic behavior of the powers of this operator. Also we…

Functional Analysis · Mathematics 2016-06-21 Fadil Chabbabi , Mostafa Mbekhta

In this paper, we establish various inequalities for some differentiable mappings that are linked with the illustrious Hermite- Hadamard integral inequality for mappings whose derivatives are (h -($\alpha$?;m))-convex.The generalized…

Functional Analysis · Mathematics 2013-04-11 Muhammad Muddassar , Muhammad Iqbal Bhatti

We prove new inequalities for the spectral radius, essential spectral radius, operator norm, measure of noncompactness and numerical radius of Hadamard weighted geometric means of positive kernel operators on Banach function and sequence…

Functional Analysis · Mathematics 2022-02-01 Katarina Bogdanović , Aljoša Peperko

Several numerical radius inequalities are studied by developing an extension of the Buzano's inequality. It is shown that if $T$ is a bounded linear operator on a complex Hilbert space, then \begin{eqnarray*} w^n(T) &\leq& \frac{1}{2^{n-1}}…

Functional Analysis · Mathematics 2023-05-30 Pintu Bhunia

By a result of Lundquist-Barrett, it follows that the rank of a positive semi-definite matrix is less than or equal to the sum of the ranks of its principal diagonal submatrices when written in block form. In this article, we take a general…

Operator Algebras · Mathematics 2018-06-19 Soumyashant Nayak

In this paper, we extend Fredholm theory in von Neumann algebras established by Breuer in [5] and [6] to spectral Fredholm theory. We consider 2 by 2 upper triangular operator matrices with coefficients in a von Neumann algebra and give the…

Operator Algebras · Mathematics 2024-03-19 Stefan Ivkovic

We present new bounds for the numerical radius of bounded linear operators and $2\times 2$ operator matrices. We apply upper bounds for the numerical radius to the Frobenius companion matrix of a complex monic polynomial to obtain new…

Functional Analysis · Mathematics 2020-01-28 Pintu Bhunia , Santanu Bag , Raj Kumar Nayak , Kallol Paul