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Related papers: The Bohr radius and the Hadamard convolution opera…

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We use variational methods to derive Hadamard-type formulae for the eigenvalues of a class of elliptic operators on a compact Riemannian manifold $M$. We then apply the latter in the following context. Consider a family of elliptic…

Differential Geometry · Mathematics 2023-06-13 Cleiton Lira Cunha , José Nazareno Vieira Gomes , Marcus Antônio Mendonça Marrocos

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

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 generalize several inequalities involving powers of the numerical radius for product of two operators acting on a Hilbert space. For any $A, B, X\in \mathbb{B}(\mathscr{H})$ such that $A,B$ are positive, we establish some numerical…

Functional Analysis · Mathematics 2015-11-09 Mostafa Sattari , Mohammad Sal Moslehian , Takeaki Yamazaki

We introduce the concepts of the Fourier transform and convolution generated by an arbitrary restriction of the differentiation operator in the space $L_{2}(0,b).$ In contrast to the classical convolution, the introduced convolution…

Analysis of PDEs · Mathematics 2013-02-07 Baltabek Kanguzhin , Niyaz Tokmagambetov

The operators of fractional calculus come in many different types, which can be categorised into general classes according to their nature and properties. We conduct a formal study of the class known as weighted fractional calculus and its…

Classical Analysis and ODEs · Mathematics 2022-02-11 Arran Fernandez , Hafiz Muhammad Fahad

A deterministic Bohmian mechanics for operators with continuous and discrete spectra is presented. Randomness enters only through initial conditions. Operators with discrete spectra are incorporated into Bohmian mechanics by associating…

Quantum Physics · Physics 2007-05-23 R. A. Hyman , Shane A. Caldwell , Edward Dalton

To study operator algebras with symmetries in a wide sense we introduce a notion of {\em relative convolution operators} induced by a Lie algebra. Relative convolutions recover many important classes of operators, which have been already…

funct-an · Mathematics 2008-02-03 Vladimir V. Kisil

Starting from a general operator representation in the time-frequency domain, this paper addresses the problem of approximating linear operators by operators that are diagonal or band-diagonal with respect to Gabor frames. A…

Analysis of PDEs · Mathematics 2008-09-17 Monika Dorfler , Bruno Torresani

Let $T$ be a bounded linear operator on a complex Hilbert space $\mathscr{H}.$ We obtain various lower and upper bounds for the numerical radius of $T$ by developing the Euclidean operator radius bounds of a pair of operators, which are…

Functional Analysis · Mathematics 2023-08-21 Suvendu Jana , 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

A general deformation of the Heisenberg algebra is introduced with two deformed operators instead of just one. This is generalised to many variables, and permits the simultaneous existence of coherent states, and the transposition of…

High Energy Physics - Theory · Physics 2009-10-22 D. B. Fairlie , J. Nuyts

Given a Hilbert module $H$ over a $C^*$-algebra, let $\mathcal{L}(H)$ be the set of all adjointable operators on $H$. For each $T\in\mathcal{L}(H)$, its numerical radius is defined by $w(T)=\sup\big\{\|\langle Tx, x \rangle\|: x\in H,…

Functional Analysis · Mathematics 2025-02-28 J. Li , K. Wu , Q. Xu

We consider the class of \emph{stable} harmonic mappings $f=h+\overline{g}$ introduced by Martin, Hernandez, and the class of \emph{stable} logharmonic mappings $f=zh\overline{g}$ introduced by AbdulHadi, El-Hajj. We determine Bohr's radius…

Complex Variables · Mathematics 2022-03-25 Zayid Abdulhadi , Layan El Hajj

The primary objective of this paper is to establish several sharp results concerning the Bohr inequality, the refined Bohr inequality, and the improved Bohr inequality for the classes of analytic functions and harmonic mappings defined on…

Complex Variables · Mathematics 2026-03-18 Vasudevarao Allu , Raju Biswas , Rajib Mandal

In this paper we show several connections between special functions arising from generalized COM-Poisson-type statistical distributions and integro-differential equations with varying coefficients involving Hadamard-type operators. New…

Probability · Mathematics 2021-01-12 Roberto Garra , Enzo Orsingher , Federico Polito

The Bohr radius for a class $\mathcal{G}$ consisting of analytic functions $f(z)=\sum_{n=0}^{\infty}a_nz^n$ in unit disc $\mathbb{D}=\{z\in\mathbb{C}:|z|<1\}$ is the largest $r^*$ such that every function $f$ in the class $\mathcal{G}$…

Complex Variables · Mathematics 2020-07-21 Swati Anand , Naveen Kumar Jain , Sushil Kumar

In this paper, a general form of integral inequalities of Hermite-Hadamard's type through differentiability for s-Convex function in second sense and whose all derivatives are absolutely continuous are established. The generalized integral…

Functional Analysis · Mathematics 2013-06-25 Muhammad Muddassar , Muhammad Iqbal Bhatti

Let $H^{\infty}(\Omega,X)$ be the space of bounded analytic functions $f(z)=\sum_{n=0}^{\infty} x_{n}z^{n}$ from a proper simply connected domain $\Omega$ containing the unit disk $\mathbb{D}:=\{z\in \mathbb{C}:|z|<1\}$ into a complex…

Complex Variables · Mathematics 2026-04-15 Vasudevarao Allu , Himadri Halder

We introduce the notions of relational groupoids and relational convolution algebras. We provide various examples arising from the group algebra of a group $G$ and a given normal subgroup $H$. We also give conditions for the existence of a…

Mathematical Physics · Physics 2021-09-22 Ivan Contreras , Nima Moshayedi , Konstantin Wernli