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Related papers: Sharpness of some Hardy-type inequalities

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The aim of this paper is to characterize in broad classes of means the so-called Hardy means, i.e., those means $M\colon\bigcup_{n=1}^\infty \mathbb{R}_+^n\to\mathbb{R}_+$ that satisfy the inequality $$ \sum_{n=1}^\infty M(x_1,\dots,x_n)…

Classical Analysis and ODEs · Mathematics 2017-06-29 Zsolt Páles , Paweł Pasteczka

A method of proving Hardy's type inequality for orthogonal expansions is presented in a rather general setting. Then sharp multi-dimensional Hardy's inequality associated with the Laguerre functions of convolution type is proved for type…

Classical Analysis and ODEs · Mathematics 2018-10-19 Paweł Plewa

Hardy's inequality on $H^p$ spaces, $p\in(0,1]$, in the context of orthogonal expansions is investigated for general basis on a subset of $\mathbb{R}^d$ with Lebesgue measure. The obtained result is applied to various Hermite, Laguerre, and…

Classical Analysis and ODEs · Mathematics 2020-05-15 Paweł Plewa

Using recent results concerning the homogenization and the Hardy property of weighted means, we establish sharp Hardy constants for concave and monotone weighted quasideviation means and for a few particular subclasses of this broad family.…

Classical Analysis and ODEs · Mathematics 2020-11-23 Zsolt Páles , Paweł Pasteczka

We give improvements and generalizations of both the classical Hardy inequality and the geometric Hardy inequality based on the divergence theorem. Especially, our improved Hardy type inequality derives both two Hardy type inequalities with…

Analysis of PDEs · Mathematics 2021-04-06 Megumi Sano

Four Jacobi settings are considered in the context of Hardy's inequality: the trigonometric polynomials and functions, and the corresponding symmetrized systems. In the polynomial cases sharp Hardy's inequality is proved for the type…

Classical Analysis and ODEs · Mathematics 2019-06-14 Paweł Plewa

We study the $P_1$ finite element approximation of the best constant in the classical Hardy inequality over bounded domains containing the origin in $\mathbb{R}^N$, for $N \geq 3$. Despite the fact that this constant is not attained in the…

Numerical Analysis · Mathematics 2025-10-06 Liviu I. Ignat , Enrique Zuazua

In the paper, by establishing the monotonicity of some functions involving the sine and cosine functions, the authors provide concise proofs of some known inequalities and find some new sharp inequalities involving the Seiffert,…

Classical Analysis and ODEs · Mathematics 2013-01-29 Wei-Dong Jiang , Feng Qi

In this paper we present a unified simple approach to anisotropic Hardy inequalities in various settings. We consider Hardy inequalities which involve a Finsler distance from a point or from the boundary of a domain. The sharpness and the…

Analysis of PDEs · Mathematics 2018-06-22 A. Mercaldo , M. Sano , F. Takahashi

We find sharp constants in fractional Hardy inequalities for weighted Triebel--Lizorkin seminorms on the whole space and half-spaces. Our results generalize recently obtained weighted fractional Hardy inequalities for Gagliardo seminorms,…

Analysis of PDEs · Mathematics 2025-12-23 Michał Kijaczko

We present a unified approach to obtain Hardy-type inequalities in the context of nilpotent Lie groups with sharp constants. The unified methodology employed herein allows for exploration of the sharp Hardy inequalities on various Lie group…

Functional Analysis · Mathematics 2023-08-04 Durvudkhan Suragan , Nurgissa Yessirkegenov

In this work we improve the sharp Hardy inequality in the case $p>n$ by adding an optimal weighted Hoelder semi-norm. To achieve this we first obtain a local improvement. We also obtain a refinement of both the Sobolev inequality for $p>n$…

Analysis of PDEs · Mathematics 2013-10-14 Georgios Psaradakis

In this thesis, we study problems at the interface of analysis and discrete mathematics. We discuss analogues of well known Hardy-type inequalities and Rearrangement inequalities on the lattice graphs $\mathbb{Z}^d$, with a particular focus…

Functional Analysis · Mathematics 2024-03-18 Shubham Gupta

We study the sharp constant in the Hardy inequality for fractional Sobolev spaces defined on open subsets of the Euclidean space. We first list some properties of such a constant, as well as of the associated variational problem. We then…

Analysis of PDEs · Mathematics 2022-09-08 Francesca Bianchi , Lorenzo Brasco , Anna Chiara Zagati

We establish an analog Hardy inequality with sharp constant involving exponential weight function. The special case of this inequality (for n=2) leads to a direct proof of Onofri inequality on S^2.

Analysis of PDEs · Mathematics 2007-10-24 Suyu Li , Meijun Zhu

The motive of this note is twofold. Inspired by the recent development of a new kind of Hardy inequality, here we discuss the corresponding Hardy-Rellich and Rellich inequality versions in the integral form. The obtained sharp Hardy-Rellich…

Functional Analysis · Mathematics 2025-05-14 Tohru Ozawa , Prasun Roychowdhury , Durvudkhan Suragan

We find best constants in several dilation invariant integral inequalities involving derivatives of functions. Some of these inequalities are new and some were known without best constants. The contents: 1. Estimate for a quadratic form of…

Analysis of PDEs · Mathematics 2008-03-10 V. Maz'ya , T. Shaposhnikova

We prove sharp inequalities of Hardy type for functions in the Sobolev space $W^{1,p}$ on the unit sphere $\mathbb{S}^{n-1}$ in $\mathbb{R}^{n}$. We achieve this in both the subcritical and critical cases. The method we use to show…

Functional Analysis · Mathematics 2020-06-15 Ahmed A. Abdelhakim

We study the behavior of the smallest possible constants $d(a,b)$ and $d_n$ in Hardy's inequalities $$ \int_a^b\left(\frac{1}{x}\int_a^xf(t)dt\right)^2\,dx\leq d(a,b)\,\int_a^b [f(x)]^2 dx $$ and $$…

Classical Analysis and ODEs · Mathematics 2024-02-07 Dimitar K. Dimitrov , Ivan Gadjev , Mourad E. H. Ismail

The aim of this paper is to characterize the so-called Hardy means, i.e., those means $M\colon\bigcup_{n=1}^\infty \mathbb{R}_+^n\to\mathbb{R}_+$ that satisfy the inequality $$ \sum_{n=1}^\infty M(x_1,\dots,x_n) \le C\sum_{n=1}^\infty x_n…

Classical Analysis and ODEs · Mathematics 2018-03-20 Zsolt Páles , Paweł Pasteczka