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Related papers: Young's (in)equality for compact operators

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We show that the validity of the non-commutative Khintchine inequality for some $q$ with $1<q<2$ implies its validity (with another constant) for all $1\le p<q$. We prove this for the inequality involving the Rademacher functions, but also…

Operator Algebras · Mathematics 2014-12-23 Gilles Pisier

Let $(\mathcal{X}, \rho, \mu)$ be a metric measure space of homogeneous type which supports a certain Poincar\'e inequality. Denote by the symbol $\mathcal{C}_{\mathrm{c}}^\ast(\mathcal{X})$ the space of all continuous functions $f$ with…

Functional Analysis · Mathematics 2021-11-19 Feng Dai , Xiaosheng Lin , Dachun Yang , Wen Yuan , Yangyang Zhang

In this paper we obtain some new refinements and reverses of Young's operator inequality. Extensions for convex functions of operators are also provided.

Functional Analysis · Mathematics 2015-10-07 Silvestru Sever Dragomir

In this paper, we show some refinements of generalized numerical radius inequalities involving the Young and Heinz inequalities. In particular, we present \begin{align*}…

Functional Analysis · Mathematics 2018-05-22 Monire Hajmohamadi , Rahmatollah Lashkaripour , Mojtaba Bakherad

We prove a sharp Lieb-Thirring type inequality for Jacobi matrices, thereby settling a conjecture of Hundertmark and Simon. An interesting feature of the proof is that it employs a technique originally used by Hundertmark-Laptev-Weidl…

Classical Analysis and ODEs · Mathematics 2021-05-18 Ari Laptev , Michael Loss , Lukas Schimmer

Let (A_0,A_1) and (B_0,B_1) be Banach couples with A_0 contained in A_1 and B_0 contained in B_1. Let T:A_1 --> B_1 be a possibly nonlinear operator which is a compact Lipschitz map of A_j into B_j for j=0,1. It is known that T maps the…

Functional Analysis · Mathematics 2009-06-16 Michael Cwikel , Alon Ivtsan

In this paper, we generalize Young's inequality for locally compact quantum groups and obtain some results for extremal pairs of Young's inequality and extremal functions of Hausdorff-Young inequality.

Operator Algebras · Mathematics 2016-11-16 Zhengwei Liu , Simeng Wang , Jinsong Wu

We establish sharp forms of Young's convolution inequality and its reverse on the discrete hypercube $\{0,1\}^d$ in the diagonal case $p=q$. As applications, we derive bounds for additive energies and sumsets. We also investigate the…

Classical Analysis and ODEs · Mathematics 2025-07-09 David Beltran , Paata Ivanisvili , José Madrid , Lekha Patil

In this paper we solve a long standing problem about the bilinear $T1$ theorem to characterize the (weighted) compactness of bilinear Calder\'{o}n-Zygmund operators. Let $T$ be a bilinear operator associated with a standard bilinear…

Classical Analysis and ODEs · Mathematics 2024-07-31 Mingming Cao , Honghai Liu , Zengyan Si , Kôzô Yabuta

In this paper, we study refinements of some inequalities related to Young inequality for scalar and for operator. As our main results, we show refined Young inequalities for two positive operators. This results refine the ordering relations…

Functional Analysis · Mathematics 2012-01-27 Shigeru Furuichi , Minghua Lin

A convolution operator in $\mathbb{R}^d$ with kernel in $L_q$ acts from $L_p$ to $L_s$, where $1/p+1/q=1+1/s$. The main theorem states that if $1<q,p,s<\infty$, then there exists an $L_p$ function of unit norm on which the $s$-norm of the…

Classical Analysis and ODEs · Mathematics 2019-10-17 Gleb Kalachev , Sergey Sadov

In this paper we characterize the compact operators on $A^p_\alpha(\mathbb{B}_n)$ when $1<p<\infty$ and $\alpha>-1$. The main result shows that an operator on $A^p_\alpha(\mathbb{B}_n)$ is compact if and only if it belongs to the Toeplitz…

Classical Analysis and ODEs · Mathematics 2013-01-22 Mishko Mitkovski , Daniel Suárez , Brett D. Wick

Let $T$ be a linear operator that, for some $p_1\in(1,\infty)$, is bounded on $L^{p_1}(\tilde w)$ for all $\tilde w\in A_{p_1}(\mathbb R^d)$ and in addition compact on $L^{p_1}(w_1)$ for some $w_1\in A_{p_1}(\mathbb R^d)$. Then $T$ is…

Functional Analysis · Mathematics 2022-02-23 Tuomas Hytönen , Stefanos Lappas

In this paper, we establish a Minkowski-type inequality for weak Lebesgue space, which allows us to obtain a characterization of relative compactness in these spaces. Furthermore, we are the first to investigate the compactness results of…

Functional Analysis · Mathematics 2023-09-20 Dinghuai Wang , Xi Hu , Shuai Qi

We characterize matrix polynomials $P,Q$ such that the inequality $$ \left\Vert Q(D)u\right\Vert _{L^{2}}\leq C\left\Vert P(D)u\right\Vert _{L^{2}}\quad\text{for all }u\in C_c^\infty(\Omega), $$ holds on bounded open sets $\Omega$. We also…

Functional Analysis · Mathematics 2026-03-05 Eduard Curcă , Bogdan Raiţă

A now classical result in the theory of variable Lebesgue spaces due to Lerner [A. K. Lerner, On modular inequalities in variable $L^p$ spaces, Archiv der Math. 85 (2005), no. 6, 538-543] is that a modular inequality for the…

Classical Analysis and ODEs · Mathematics 2017-10-23 David Cruz-Uribe , Giovanni Di Fratta , Alberto Fiorenza

Let $1 < p_1, \ldots, p_n < \infty, 1\leq q < \infty$ be such that $\sum\limits_{i=1}^n \frac{1}{p_i} < \frac{1}{q}$ and let $\mu_1, \ldots, \mu_n, \nu$ be arbitrary measures. Generalizing known linear and multilinear results, we prove that…

Functional Analysis · Mathematics 2025-09-08 Geraldo Botelho , Vinicius C. C. Miranda

We prove an analogous Hanner's Inequality of $L^p$ spaces for positive semidefinite matrices. Let $||X||_p=\text{Tr}[(X^\ast X)^{p/2}]^{1/p}$ denote the $p$-Schatten norm of a matrix $X\in M_{n\times n}(\mathbb{C})$. We show that the…

Functional Analysis · Mathematics 2022-05-19 Victoria M. Chayes

We establish upper bounds for the convolution operator acting between interpolation spaces. This will provide several examples of Young Inequalities in different families of function spaces. We use this result to prove a bilinear…

Functional Analysis · Mathematics 2017-05-18 Pedro Fernández-Martínez , Eduardo Brandani da Silva

A classification of weakly compact multiplication operators on L(L_p), $1<p<\infty$, is given. This answers a question raised by Saksman and Tylli in 1992. The classification involves the concept of $\ell_p$-strictly singular operators, and…

Functional Analysis · Mathematics 2007-08-06 William B. Johnson , Gideon Schechtman