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Related papers: More accurate numerical radius inequalities (II)

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New proofs of the classical Hermite-Hadamard inequality are presented and several applications are given, including Hadamard-type inequalities for the functions, whose derivatives have inflection points or whose derivatives are convex.…

General Mathematics · Mathematics 2020-10-14 Ilham A. Aliev , Mehmet E. Tamar , Cagla Sekin

We investigate some aspects of various numerical radius orthogonalities and numerical radius parallelism for bounded linear operators on a Hilbert space $\mathscr{H}$. Among several results, we show that if $T,S\in \mathbb{B}(\mathscr{H})$…

Functional Analysis · Mathematics 2020-04-07 Maryam Torabian , Maryam Amyari , Marzieh Moradian Khibary

Here, we study the $q$-numerical radius of rank-one operators on a Hilbert space $\mathcal{H}$. More precisely, for $q \in [0,1]$ and $a, b \in \mathcal{H}$, we establish the formula \[ \omega_q(a \otimes b) = \frac{1}{2}\left(\|a\|\|b\| +…

Functional Analysis · Mathematics 2025-03-10 Dušan Denčić , Hranislav Stanković , Mihailo Krstić , Ivan Damnjanović

Let $A$ be a positive definite operator on a Hilbert space $H$, and $|||.|||$ be a unitarily invariant norm on $B(H)$. We show that if $f$ is an operator monotone function on $(0,\infty)$ and $n\in \mathbb{N}$, then $|||D^n…

Functional Analysis · Mathematics 2021-05-13 Amir Ghasem Ghazanfari

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,…

Operator Algebras · Mathematics 2024-11-08 Saikat Mahapatra , Riddhick Birbonshi , Arnab Patra

A mapping M(t) is considered to obtain some preliminary results and a new trapezoidal form of Fejer inequality related to the h-convex functions. Furthermore the obtained results are applied to achieve some new inequalities in connection…

Functional Analysis · Mathematics 2019-02-19 M. Rostamian Delavar , S. S. Dragomir

An operator $T$ acting on a Hilbert space is called $(\alpha ,\beta)$-normal ($0\leq \alpha \leq 1\leq \beta $) if \begin{equation*} \alpha ^{2}T^{\ast }T\leq TT^{\ast}\leq \beta ^{2}T^{\ast}T. \end{equation*} In this paper we establish…

Functional Analysis · Mathematics 2008-04-30 Sever S. Dragomir , Mohammad Sal Moslehian

In this paper, we establish some new Hadamard type inequalities for s-logarithmically convex functions in the second sense via fractional integrals by using Lemma 1 which has been proved by Sarikaya et al. in the paper [3].

Functional Analysis · Mathematics 2012-12-10 Havva Kavurmaci , Mevlut Tunc

The celebrated Heinz inequality asserts that $ 2|||A^{1/2}XB^{1/2}|||\leq |||A^{\nu}XB^{1-\nu}+A^{1-\nu}XB^{\nu}|||\leq |||AX+XB|||$ for $X \in \mathbb{B}(\mathscr{H})$, $A,B\in \+$, every unitarily invariant norm $|||\cdot|||$ and $\nu \in…

Functional Analysis · Mathematics 2021-07-23 R. Kaur , M. S. Moslehian , M. Singh , C. Conde

Let $ \mathcal{S}(p) $ be the class of all meromorphic univalent functions defined in the unit disc $ \mathbb{D} $ of the complex plane with a simple pole at $ z=p $ and normalized by the conditions $ f(0)=0 $ and $ f^{\prime}(0)=1 $. In…

Complex Variables · Mathematics 2024-07-02 Molla Basir Ahamed , Rajesh Hossain

Relatively recently, K.M.R. Audenaert (2010), R.A. Horn and F. Zhang (2010), Z. Huang (2011), A.R. Schep (2011), A. Peperko (2012), D. Chen and Y. Zhang (2015) have proved inequalities on the spectral radius and the operator norm of…

Functional Analysis · Mathematics 2017-12-18 Roman Drnovšek , Aljoša Peperko

The object of the present paper is to study of radius of convexity two certain integral operators as follows \begin{equation*} F(z):=\int_{0}^{z}\prod_{i=1}^{n}\left(f'_i(t)\right)^{\gamma_i}{\rm d}t \end{equation*} and \begin{equation*}…

Complex Variables · Mathematics 2018-04-12 P. Najmadi , Sh. Najafzadeh , A. Ebadian

Let $A=[A_{ij}]$ be an $n\times n$ operator matrix where each $A_{ij}$ is a bounded linear operator on a complex Hilbert space $\mathcal{H}$. With other numerical radius bounds via contraction operators, we show that $w(A) \leq…

Functional Analysis · Mathematics 2024-07-10 Pintu Bhunia

Many classical geometric inequalities on functionals of convex bodies depend on the dimension of the ambient space. We show that this dimension dependence may often be replaced (totally or partially) by different symmetry measures of the…

Metric Geometry · Mathematics 2014-12-11 René Brandenberg , Stefan König

In this note, we present a refinement of the well-known AM-GM inequality. We use this improved inequalty to establish corresponding inequalities on Hilbert space. We also give some refinements of the Kantorovich inequality.

Functional Analysis · Mathematics 2021-11-08 Mehdi Eghbali Amlashi , Mahmoud Hassani

Denote by w(A) the numerical radius of a bounded linear operator A acting on Hilbert space. Suppose that A is invertible and that the numerical radius of A and of its inverse are no greater than 1+e for some non-negative e. It is shown that…

Functional Analysis · Mathematics 2018-06-05 Catalin Badea , Michel Crouzeix

In this paper, we introduce the notion of (g,\Phi_{h})-convex dominated function and present some properties of them. Finally, we present a version of Hermite-Hadamard-type inequalities for (g,\Phi_{h})-convex dominated functions. Our…

Classical Analysis and ODEs · Mathematics 2012-08-07 M. Emin Ozdemir , Mustafa Gurbuz , Havva Kavurmaci

This article introduces several new relations among related Hilbert space operators. In particular, we prove some L\"{o}ewner partial orderings among $T, |T|, \mathcal{R}T, \mathcal{I}T, |T|+|T^*|$ and many other related forms, as a new…

Functional Analysis · Mathematics 2023-03-08 Mohammad Sababheh , Hamid Reza Moradi

In this paper, we establish some weighted fractional inequalities for differentiable mappings whose derivatives in absolute value are convex. These results are connected with the celebrated Hermite-Hadamard-Fejer type integral inequality.…

Classical Analysis and ODEs · Mathematics 2014-09-19 Erhan Set , Imdat Iscan , M. Zeki Sarikaya , M. Emin Ozdemir

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