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It is shown that the right shift semigroup on $L^2(\mathbb{R}_+)$ does not satisfy the weighted Weiss conjecture for $\alpha \in (0,1)$. In other words, $\alpha$-admissibility of scalar valued observation operators cannot always be…

Functional Analysis · Mathematics 2009-04-29 Andrew Wynn

We prove a Weiss conjecture on $\beta$-admissibility of control and observation operators for discrete and continuous $\gamma$-hypercontractive semigroups of operators, by representing them in terms of shifts on weighted Bergman spaces and…

Analysis of PDEs · Mathematics 2016-01-15 Birgit Jacob , Jonathan R. Partington , Sandra Pott , Andrew Wynn

In this note we show that for analytic semigroups the so-called Weiss condition of uniform boundedness of the operators $Re(\lambda)^\einhalb C(\lambda+A)^{-1}, \qquad Re(\lambda)>0$ on the complex right half plane and weak Lebesgue…

Optimization and Control · Mathematics 2012-06-25 Bernhard Hermann Haak

Let T : X --> X$ be a power bounded operator on Banach space. An operator C : X --> Y$ is called admissible for T if it satisfies an estimate $\sum_k\norm{CT^k(x)}^2\,\leq M^2\norm{x}^2$. Following Harper and Wynn, we study the validity of…

Functional Analysis · Mathematics 2013-01-22 Christian Le Merdy

We say that a weighted shift $W_\alpha$ with (positive) weight sequence $\alpha: \alpha_0, \alpha_1, \ldots$ is {\it moment infinitely divisible} (MID) if, for every $t > 0$, the shift with weight sequence $\alpha^t: \alpha_0^t, \alpha_1^t,…

Functional Analysis · Mathematics 2019-10-22 Chafiq Benhida , Raul E. Curto , George R. Exner

Let $\gamma_{-1}$ be the absolutely continuous measure on $\mathbb{R}^n$ whose density is the reciprocal of a Gaussian and consider the natural weighted Laplacian $\mathcal{A}$ on $L^2(\gamma_{-1})$. In this paper, we prove boundedness and…

Functional Analysis · Mathematics 2018-01-30 Tommaso Bruno

We consider a conjecture attributed to Muckenhoupt and Wheeden which suggests a positive relationship between the continuity of the Hardy-Littlewood maximal operator and the Hilbert transform in the weighted setting. Although continuity of…

Classical Analysis and ODEs · Mathematics 2011-09-12 Maria Carmen Reguera , James Scurry

In this paper we initiate the study of a fundamental yet untapped random model of non-selfadjoint, bounded linear operators acting on a separable complex Hilbert space. We replace the weights $w_n=1$ in the classical unilateral shift $T$,…

Functional Analysis · Mathematics 2018-11-15 Guozheng Cheng , Xiang Fang , Sen Zhu

This paper studies the behaviour of iterates of weighted composition operators acting on spaces of analytic functions, with particular emphasis on the Hardy space $H^2$. Questions relating to uniform, strong and weak convergence are…

Functional Analysis · Mathematics 2020-02-11 I. Chalendar , J. R. Partington

In this note, we completely characterize complex symmetric weighted composition differentiation operator on the Hardy space $H^2$ with respect to the conjugation operator $C_{\lambda,\alpha}$. Meanwhile, the normal and self-adjoint of the…

Functional Analysis · Mathematics 2020-11-17 Junming Liu , Saminathan Ponnusamy , Huayou Xie

In this article, we study the weighted composition operators preserving the class $\mathcal{P}_{\alpha}$ of analytic functions subordinate to $\frac{1+\alpha z}{1-z}$ for $|\alpha|\leq 1, \alpha \neq -1$. Some of its consequences and…

Functional Analysis · Mathematics 2018-02-07 Perumal Muthukumar , Saminathan Ponnusamy

We reconsider studies of Toeplitz operators on function spaces (the weighted Bergman space, the generalized derivative Hardy space) and the H-Toeplitz operators on the Bergman space. Past studies have considered the presence or absence of…

Functional Analysis · Mathematics 2024-09-20 Chafiq Benhida , George R. Exner , Ji Eun Lee , Jongrak Lee

We verify conjecture 5.11 of Panyushev [\emph{Antichains in weight posets associated with gradings of simple Lie algebras}, Math Z 281(3):1191--1214, 2015].

Representation Theory · Mathematics 2015-12-08 Chao-Ping Dong

We prove weighted estimates for singular integral operators which operate on function spaces on a half-line. The class of admissible weights includes Muckenhoupt weights and weights satisfying Sawyer's one-sided conditions. The kernels of…

Classical Analysis and ODEs · Mathematics 2014-10-15 Ralph Chill , Sebastian Krol

We characterize a three-weight inequality for an iterated discrete Hardy-type operator. In the case when the domain space is a weighted space $\ell^p$ with $p\in(0,1]$, we develop characterizations which enable us to reduce the problem to…

Functional Analysis · Mathematics 2019-03-12 Amiran Gogatishvili , Martin Křepela , Rastislav Oľhava , Luboš Pick

We dominate non-integral singular operators by adapted sparse operators and derive optimal norm estimates in weighted spaces. Our assumptions on the operators are minimal and our result applies to an array of situations, whose prototype are…

Classical Analysis and ODEs · Mathematics 2016-08-03 Frédéric Bernicot , Dorothee Frey , Stefanie Petermichl

Let $L=-\Delta+V$ be a Schr\"odinger operator acting on $L^2(\mathbb R^n)$, $n\ge1$, where $V\not\equiv 0$ is a nonnegative locally integrable function on $\mathbb R^n$. In this article, we will introduce weighted Hardy spaces $H^p_L(w)$…

Classical Analysis and ODEs · Mathematics 2011-03-01 Hua Wang

We consider several weak type estimates for singular operators using the Bellman function approach. We disprove the $A_1$ conjecture, thus strengthening the counterexamples built by Reguera--Thiele. We show a certain logarithmic blow-up for…

Analysis of PDEs · Mathematics 2015-06-16 F. Nazarov , A. Reznikov , V. Vasyunin , A. Volberg

We prove an extrapolation result for general operators under some weak assumptions on the boundedness of the operator. In particular, we show that if the operator is weakly bounded on some L^{p_{0}}(w), for all "flat" weights, w in…

Classical Analysis and ODEs · Mathematics 2012-04-19 Nicholas Boros , Nikolaos Pattakos , Alexander Volberg

In this paper, we consider a weighted version of one-dimensional discrete Hardy inequalities with power weights of the form $n^\alpha$. We prove the inequality when $\alpha$ is an even natural number with the sharp constant and remainder…

Functional Analysis · Mathematics 2024-03-12 Shubham Gupta
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