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Related papers: Sharp $ A_2$ Inequality for Haar Shift Operators

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We prove the Central Limit Theorem (CLT) from the definition of weak convergence using the Haar wavelet basis, calculus, and elementary probability. The use of the Haar basis pinpoints the role of $L^{2}([0,1])$ in the CLT as well as the…

Probability · Mathematics 2015-10-29 Vladimir Dobric , Patricia Garmirian

We discuss weighted estimates for the squares of the Riesz transforms, R^{2}, on L^{2}(W) where W is a matrix A2 weight. We prove that if W is close to the Identity matrix Id, then the operator norm of R^{2} is close to its unweighted norm…

Classical Analysis and ODEs · Mathematics 2013-03-29 Nicholas Boros , Nikolaos Pattakos

Here we show that Lerner's method of local mean oscillation gives a simple proof of the $A_2$ conjecture for spaces of homogeneous type: that is, the linear dependence on the $A_2$ norm for weighted $L^2$ Calderon-Zygmund operator…

Classical Analysis and ODEs · Mathematics 2012-06-13 Theresa C. Anderson , Armen Vagharshakyan

Recently the matrix $A_2$ conjecture was disproved. Indeed, the growth of the vector Hilbert transform in the matrix weighted $L^2(W)$ space was shown to be at best a constant multiple of $[W]_{\mathbf{A}_2}^{3/2}$. This bound had…

Classical Analysis and ODEs · Mathematics 2026-05-20 Komla Domelevo , Spyridon Kakaroumpas , Stefanie Petermichl , Sergei Treil , Alexander Volberg

We prove that the analogue for the Hilbert transform of a classical weighted inequality by Fefferman and Stein for the Hardy Littlewood maximal operator does not hold. This is a sequel to paper arXiv:1008.3943 by the first author, which…

Classical Analysis and ODEs · Mathematics 2010-11-09 Maria Carmen Reguera , Christoph Thiele

In this paper, we give necessary and sufficient conditions for weighted $L^2$ estimates with matrix-valued measures of well localized operators. Namely, we seek estimates of the form: \[ \| T(\mathbf{W} f)\|_{L^2(\mathbf{V})} \le…

Functional Analysis · Mathematics 2016-11-22 Kelly Bickel , Amalia Culiuc , Sergei Treil , Brett D. Wick

The generalized Parseval equality for the Mellin transform is employed to prove the inversion theorem in L_2 with the respective inverse operator related to the Hartley transform on the nonnegative half-axis (the half-Hartley transform).…

Classical Analysis and ODEs · Mathematics 2014-03-11 Semyon Yakubovich

Given a Muckenhoupt weight $w$ and a second order divergence form elliptic operator $L$, we consider different versions of the weighted Hardy space $H^1_L(w)$ defined by conical square functions and non-tangential maximal functions…

Classical Analysis and ODEs · Mathematics 2018-10-10 José María Martell , Cruz Prisuelos-Arribas

We study a restriction of the Hilbert transform as an operator $H_T$ from $L^2(a_2,a_4)$ to $L^2(a_1,a_3)$ for real numbers $a_1 < a_2 < a_3 < a_4$. The operator $H_T$ arises in tomographic reconstruction from limited data, more precisely…

Functional Analysis · Mathematics 2013-11-28 Reema Al-Aifari , Alexander Katsevich

We prove sharp $L^p(w)$ norm inequalities for the intrinsic square function (introduced recently by M. Wilson) in terms of the $A_p$ characteristic of $w$ for all $1<p<\infty$. This implies the same sharp inequalities for the classical…

Classical Analysis and ODEs · Mathematics 2010-05-11 Andrei K. Lerner

The purpose of this note is to show that the di-bar-estimate which is needed in the Ohsawa-Takegoshi Extension Theorem [6] is a direct consequence of the Hormander-Kohn-Morrey weigthed inequality. In this inequality, the Donnelly-Fefferman…

Complex Variables · Mathematics 2015-05-05 Luca Baracco

By H\"ormander's $L^2$-m\'ethode, we study some operators in the Hilbert space of weight $L^2(\mathbb{C}, \mathrm{e}^{-|z|^2})$. We prove in each case of operator the existence of its inverse which is also a bounded operator.

Complex Variables · Mathematics 2022-07-01 Souhaibou Sambou

The simplest and most natural examples of completely nonunitary contractions on separable complex Hilbert spaces which have polynomial characteristic functions are the nilpotent operators. The main purpose of this paper is to prove the…

Functional Analysis · Mathematics 2017-04-20 Ciprian Foias , Carl Pearcy , Jaydeb Sarkar

We consider a two weight $L^{p}(\mu) \to L^{q}(\nu)$-inequality for well localized operators as defined and studied by F. Nazarov, S. Treil and A. Volberg when $p=q=2$. A counterexample of F. Nazarov shows that the direct analogue of these…

Classical Analysis and ODEs · Mathematics 2016-01-27 Emil Vuorinen

We prove $\mathrm{H}^1$ and $\mathrm{BMO}$ endpoint inequalities for generic cancellative Haar shifts defined with respect to a possibly non-homogeneous Borel measure $\mu$ satisfying a weak regularity condition. This immediately yields a…

Classical Analysis and ODEs · Mathematics 2024-12-18 José M. Conde Alonso , Nathan A. Wagner

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

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

We prove a limited range, off-diagonal extrapolation theorem that generalizes a number of results in the theory of Rubio de Francia extrapolation, and use this to prove a limited range, multilinear extrapolation theorem. We give two…

Classical Analysis and ODEs · Mathematics 2018-10-10 David Cruz-Uribe , José María Martell

Let $T$ be an $L^2$-bounded operator having an $\omega$-Calder\'on--Zygmund kernel $K$ with a modulus of continuity $\omega$. If $\omega$ satisfied the Dini condition $\int_0^1\omega(t)\ud t/t<\infty$, then $T$ satisfies the $A_2$ theorem…

Classical Analysis and ODEs · Mathematics 2013-04-30 Tuomas P. Hytönen

In this paper we consider a stronger property than the Bishop-Phelps-Bollob\'{a}s property for various classes of operators on a complex Hilbert space. The Bishop-Phelps-Bollob\'as {\it point} property for some class $\mathcal{A} \subset…

Functional Analysis · Mathematics 2019-11-04 Yun Sung Choi , Sheldon Dantas , Mingu Jung
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