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In this paper we use basic properties of strongly convex functions to obtain new inequalities including Jensen's type and Jensen-Mercer type inequalities. Applications for special means are pointed out as well. We also give a Jensen's…

Functional Analysis · Mathematics 2017-07-06 H. R. Moradi , M. E. Omidvar , M. Adil Khan , K. Nikodem

In this paper we consider a generalized version of Carleman's inequality. An equivalent version of it states that $\|f\|_{A_\alpha^{2\alpha}}\leq\|f\|_{H^2}$, where $f$ is a holomorphic function and $\alpha>1$. If the norms…

Functional Analysis · Mathematics 2019-08-06 Hui Dan , Kunyu Guo , Yi Wang

We study a family of fractional integral operator defined on an homogeneous space with a "rectangle doubling" measure. As a result, we give an extension of the classical Hardy-Littlewood-Sobolev theorem to a multi-parameter setting.

Classical Analysis and ODEs · Mathematics 2022-02-23 Zipeng Wang

In this paper, we give some refinements for the second inequality in $\frac{1}{2}\|A\| \leq w(A) \leq \|A\|$, where $A\in B(H)$. In particular, if $A$ is hyponormal by refining the Young inequality with the Kantorovich constant $K(\cdot,…

Functional Analysis · Mathematics 2020-10-13 Zahra Heydarbeygi , Maryam Amyari , Mahnaz Khanehgir

Alexandrov's inequalities imply that for any convex body $A$, the sequence of intrinsic volumes $V_1(A),\ldots,V_n(A)$ is non-increasing (when suitably normalized). Milman's random version of Dvoretzky's theorem shows that a large initial…

Metric Geometry · Mathematics 2017-02-22 Grigoris Paouris , Peter Pivovarov , Petros Valettas

For a self-adjoint unbounded operator D on a Hilbert space H, a bounded operator y on H and some complex Borel functions g(t) we establish inequalities of the type ||[g(D),y]|| \leq A|||y|| + B||[D,y]|| + ...+ X|[D, [D,...[D, y]...]]||. The…

Functional Analysis · Mathematics 2015-12-17 Erik Christensen

Let $(G, 1_G)$ be a finite group and let $S=g_1\bdot \ldots\bdot g_{\ell}$ be a nonempty sequence over $G$. We say $S$ is a tiny product-one sequence if its terms can be ordered such that their product equals $1_G$ and…

Number Theory · Mathematics 2020-02-28 Qinghai Zhong

New inequalities for the $A$-numerical radius of the products and sums of operators acting on a semi-Hilbert space, i.e. a space generated by a positive semidefinite operator $A$, are established. In particular, it is proved for operators…

Functional Analysis · Mathematics 2020-12-23 Pintu Bhunia , Kais Feki , Kallol Paul

We obtain the inequality $$\int_{\Omega}|\nabla u(x)|^ph(u(x))dx\leq C(n,p)\int_{\Omega} \left( \sqrt{ |\nabla^{(2)} u(x)||{\cal T}_{h,C}(u(x))|}\right)^{p}h(u(x))dx,$$ where $\Omega\subseteq {\bf R}^n$ and $n\ge 2$, $u:\Omega\rightarrow…

Analysis of PDEs · Mathematics 2016-11-29 Tomasz Choczewski , Agnieszka Kałamajska

In this paper, we prove the following reversed Hardy-Littlewood-Sobolev inequality with extended kernel \begin{equation*} \int_{\mathbb{R}_+^n}\int_{\partial\mathbb{R}^n_+} \frac{x_n^\beta}{|x-y|^{n-\alpha}}f(y)g(x) dydx\geq…

Analysis of PDEs · Mathematics 2020-06-09 Wei Dai , Yunyun Hu , Zhao Liu

We prove several numerical radius inequalities for linear operators in Hilbert spaces. It is shown, among other inequalities, that if $A$ is a bounded linear operator on a complex Hilbert space, then \[\omega \left( A \right)\le…

Functional Analysis · Mathematics 2021-06-15 Farzaneh Pouladi Najafabadi , Hamid Reza Moradi

We prove a new inequality which improves on the classical Hardy inequality in the sense that a nonlinear integral quantity with super-quadratic growth, which is computed with respect to an inverse square weight, is controlled by the energy.…

Analysis of PDEs · Mathematics 2010-10-29 Manuel Del Pino , Jean Dolbeault , Stathis Filippas , Achiles Tertikas

In this work, some generalizations and refinements inequalities for numerical radius of the product of Hilbert space operators are proved. New inequalities for numerical radius of block matrices of Hilbert space operators are also…

Functional Analysis · Mathematics 2019-03-18 Mohammad W. Alomari

An inverse problem is considered for an inhomogeneous Schr\"odinger equation. Assuming that the potential vanishes outside a finite interval and satisfies some other technical assumptions, one proves the uniqueness of the recovery of this…

Mathematical Physics · Physics 2009-10-31 A. G. Ramm

In this paper we establish the reversed sharp Hardy-Littlewood-Sobolev (HLS for short) inequality on the upper half space and obtain a new HLS type integral inequality on the upper half space (extending an inequality found by Hang, Wang and…

Analysis of PDEs · Mathematics 2017-03-09 Jingbo Dou , Qianqiao Guo , Meijun Zhu

In this paper is defined an $n$-inner product of type $\langle {\bf a}_1,\cdots ,{\bf a}_n\vert {\bf b}_1\cdots {\bf b}_n\rangle $ where ${\bf a}_1,\cdots ,{\bf a}_n$, ${\bf b}_1, \cdots ,{\bf b}_n$ are vectors from a vector space $V$. This…

General Mathematics · Mathematics 2025-01-29 Kostadin Trenčevski , Risto Malčeski

We consider the optimization problem corresponding to the sharp constant in a conformally invariant Sobolev inequality on the $n$-sphere involving an operator of order $2s> n$. In this case the Sobolev exponent is negative. Our results…

Analysis of PDEs · Mathematics 2023-07-24 Rupert L. Frank , Tobias König , Hanli Tang

Various inequalities exist between the area of a triangle, the perimeter squared $(a+b+c)^2$ and the isoperimetric deficit $Q=(a-b)^2+(b-c)^2+(c-a)^2$. The direct and reverse Finsler-Hadwiger inequalities correspond to the best linear…

Optimization and Control · Mathematics 2025-08-11 Beniamin Bogosel

We study the Cauchy--Schwarz and some related inequalities in a semi-inner product module over a $C^*$-algebra $\A$. The key idea is to consider a semi-inner product $\A$-module as a semi-inner product $\A$-module with respect to another…

Operator Algebras · Mathematics 2012-03-22 LJ. Arambasic , D. Bakic , M. S. Moslehian

Let $F$ be a field and a finite $A\subset F$ be sufficiently small in terms of the characteristic $p$ of $F$ if $p>0$. We strengthen the "threshold" sum-product inequality $$|AA|^3 |A\pm A|^2 \gg |A|^6\,,\;\;\;\;\mbox{hence} \;\;…

Combinatorics · Mathematics 2018-09-27 Misha Rudnev , George Shakan , Ilya Shkredov