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Related papers: Noncommutative sharp dual Doob inequalities

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We prove that for any (trace-preserving) conditional expectation $\mathcal E$ on a noncommutative $L_p$ with $p>2$, $Id-\mathcal E$ is a contraction on the positive cone $L_p^+$.

Operator Algebras · Mathematics 2016-01-28 Éric Ricard

We study the dual space of the variable Lebesgue space $\Lp$ with unbounded exponent function $\pp$ and provide an answer to a question posed in~[fiorenza-cruzuribe2013]. Our approach is to decompose the dual into a topological direct sum…

Classical Analysis and ODEs · Mathematics 2019-09-16 Alex Amenta , Jose M. Conde-Alonso , David Cruz-Uribe , Jesus Ocariz

Let $(\lambda_n)_{n \geq 1}$ be a non-negative sequence with $\lambda_1>0$ and let $\Lambda_n=\sum^n_{i=1}\lambda_i$. We study the following Copson inequality for $0<p<1$, $L>p$, \begin{align*} \sum^{\infty}_{n=1}\left (\frac 1{\Lambda_n}…

Classical Analysis and ODEs · Mathematics 2018-06-21 Peng Gao , Huayu Zhao

In this paper, we obtain the desired noncommutative maximal inequalities of the truncated Calder\'on-Zygmund operators of non-convolution type acting on operator-valued $L_p$-functions for all $1<p<\infty$, answering a question left open in…

Functional Analysis · Mathematics 2022-12-27 Guixiang Hong , Xudong Lai , Samya Kumar Ray , Bang Xu

We introduce the mixed-norm amalgam spaces $(L^{\vec{p}},L^{\vec{s}})(\mathbb{R}^n)$ and $(L^{\vec{p}},L^{\vec{s}})^{\alpha}(\mathbb{R}^n)$, and show their some basic properties. In addition, we find the predual…

Functional Analysis · Mathematics 2021-10-05 Houkun Zhang , Jiang Zhou

In this paper, we study both elliptic and parabolic equations in non-divergence form with singular degenerate coefficients. Weighted and mixed-norm $L_p$-estimates and solvability are established under some suitable partially weighted BMO…

Analysis of PDEs · Mathematics 2018-11-21 Hongjie Dong , Tuoc Phan

We prove that non-commutative martingale transforms are of weak type $(1,1)$. More precisely, there is an absolute constant $C$ such that if $\M$ is a semi-finite von Neumann algebra and $(\M_n)_{n=1}^\infty$ is an increasing filtration of…

Functional Analysis · Mathematics 2007-05-23 Narcisse Randrianantoanina

In this paper we study Johnson-Schechtman inequalities for noncommutative martingales. More precisely, disjointification inequalities of noncommutative martingale difference sequences are proved in an arbitrary symmetric operator space…

Probability · Mathematics 2016-12-15 Yong Jiao , Fedor Sukochev , Dmitriy Zanin , Dejian Zhou

In the present paper we introduce the notion of strongly orthogonal martingales. Moreover, we show that for any UMD Banach space $X$ and for any $X$-valued strongly orthogonal martingales $M$ and $N$ such that $N$ is weakly differentially…

Probability · Mathematics 2018-12-20 Ivan Yaroslavtsev

In this note, we prove a sharp large derivation principle (LDP) for the cubic nonlinear Schr\"odinger equation with Gaussian random initial data in Fourier Lebesgue spaces. As a consequence, we improve the exponential decay condition in…

Analysis of PDEs · Mathematics 2025-12-09 Rui Liang , Yuzhao Wang

We consider uniformly parabolic equations and inequalities of second order in the non-divergence form with drift \[-u_{t}+Lu=-u_{t}+\sum_{ij}a_{ij}D_{ij}u+\sum b_{i}D_{i}u=0\,(\geq0,\,\leq0)\] in some domain $Q\subset \mathbb{R}^{n+1}$. We…

Analysis of PDEs · Mathematics 2016-02-03 Gong Chen

We establish an Azuma type inequality under a Lipshitz condition for martingales in the framework of noncommutative probability spaces and apply it to deduce a noncommutative Heoffding inequality as well as a noncommutative McDiarmid type…

Operator Algebras · Mathematics 2021-07-23 Ghadir Sadeghi , Mohammad Sal Moslehian

We explicitly describe the Haagerup and the Kosaki non-commutative $L^p$-spaces associated with a tensor product von Neumann algebra $M_1\bar{\otimes}M_2$ in terms of those associated with $M_i$ and usual tensor products of unbounded…

Operator Algebras · Mathematics 2024-07-09 Shinya Kato , Yoshimichi Ueda

We consider structured optimisation problems defined in terms of the sum of a smooth and convex function, and a proper, l.s.c., convex (typically non-smooth) one in reflexive variable exponent Lebesgue spaces $L_{p(\cdot)}(\Omega)$. Due to…

Optimization and Control · Mathematics 2022-11-10 Marta Lazzaretti , Luca Calatroni , Claudio Estatico

Let $\mathfrak A$ be a type 1 subdiagonal algebra in a $\sigma$-finite von Neumann algebra $\mathcal M$ with respect to a faithful normal conditional expectation $\Phi$. We consider a Riesz type factorization theorem in noncommutative $H^p$…

Operator Algebras · Mathematics 2021-01-12 Ruihan Zhang , Guoxing Ji

The paper makes the first steps into the study of extensions ("twisted sums") of noncommutative $L^p$-spaces regarded as Banach modules over the underlying von Neumann algebra $\mathcal M$. Our approach combines Kalton's description of…

Operator Algebras · Mathematics 2016-02-02 Félix Cabello Sánchez , Jesús M. F. Castillo , Stanislaw Goldstein , Jesús Suárez

In the present work we give a simple method to obtain weighted norm inequalities in Lebesgue spaces $L_{p,\gamma }$ with Muckenhoupt weights $\gamma $. This method is different from celebrated Extrapolation or Interpolation Theory. In this…

Classical Analysis and ODEs · Mathematics 2021-09-06 Ramazan Akgün

We investigate a class of variable growth nonlocal differential equations of Kirchhoff-type having the general form \(-A\!\left(\int_0^1 b(1-s)\,\big(u(s)\big)^{p(s)}\,ds\right)\,u''(t) = \lambda\,f(t,u(t))\) for \(t\in(0,1)\), where \(A\)…

General Mathematics · Mathematics 2025-12-01 Christopher S. Goodrich , Gabriel Nakhl

Let $ m, n $ be integers such that $ \frac{n}{2} > m \geq 1 $ and let $ (M, g) $ be a closed $ n-$dimensional Riemannian manifold. We prove there exists some $ B \in \mathbb{R} $ depending only on $ (M, g) $, $ m $, and $ n $ such that for…

Analysis of PDEs · Mathematics 2024-09-16 Samuel Zeitler

We show that for a quantum $L^p$-martingale $(X(t))$, $p>2$, there exists a Doob-Meyer decomposition of the submartingale $(|X(t)|^2)$. A noncommutative counterpart of a classical process continuous with probability one is introduced, and a…

Operator Algebras · Mathematics 2007-05-23 Andrzej Luczak