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Related papers: The matrix $A_2$ conjecture fails, i.e. $3/2>1$

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We consider here a problem of finding the sharp estimate for the boundedness of an arbitrary Calder\'on-Zygmund operator in $L^2(w)$, $w\in A_2$. We first prove that for $A_2$ weight $w$ one has that the norm a Calderon--Zygmund operator…

Analysis of PDEs · Mathematics 2010-06-15 Carlos Perez , Sergei Treil , Alexander Volberg

Following the ideas of A. Lerner, F. Nazarov, S. Ombrosi from [12] we prove that there is a sequence of weights $w\in A^d_1$ such that $[w]^d_{A_1}\to \infty$, and martingale transforms $T$ such that with an absolute positive $c$ $\|T:…

Analysis of PDEs · Mathematics 2018-04-10 Paata Ivanisvili , Alexander Volberg

It is well-known that dyadic martingale transforms are a good model for Calder\'on-Zygmund singular integral operators. In this paper we extend some results on weighted norm inequalities to vector-valued functions. We prove that, if $W$ is…

Classical Analysis and ODEs · Mathematics 2017-08-02 Sandra Pott , Andrei Stoica

Matrix weights satisfying a Muckenhoupt $A_p$-condition relative to a family of anisotropic balls in $\mathbb{R}^d$ defined by a pseudo-metric are studied. It is shown that such matrix weights satisfy a doubling condition and a reverse…

Functional Analysis · Mathematics 2025-10-06 Morten Nielsen

Landau-Ginzburg mirror symmetry predicts isomorphisms between graded Frobenius algebras (denoted $\mathcal{A}$ and $\mathcal{B}$) that are constructed from a nondegenerate quasihomogeneous polynomial $W$ and a related group of symmetries…

Algebraic Geometry · Mathematics 2018-06-29 Nathan Cordner

Very recently, Bo\v{z}in and Karapetrovi\'c solved a conjecture by proving that the norm of the Hilbert matrix operator $\mathcal{H}$ on the Bergman space $A^p$ is equal to $\frac{\pi}{\sin(\frac{2\pi}{p})}$ for $2 < p < 4.$ In this article…

Functional Analysis · Mathematics 2018-05-22 Mikael Lindström , Santeri Miihkinen , Niklas Wikman

Let $A$ be a complex square matrix, and write its polar decomposition as $A=U|A|$. For $0<\lambda<1$, the $\lambda$-Aluthge transform of $A$ is defined by $$ \Delta_\lambda(A)=|A|^\lambda U|A|^{1-\lambda}. $$ In 2007, Huang and Tam…

Functional Analysis · Mathematics 2026-03-06 Teng Zhang

For an L ^2-bounded Calderon-Zygmund Operator T, and a weight w \in A_2, the norm of T on L ^2 (w) is dominated by A_2 characteristic of the weight. The recent theorem completes a line of investigation initiated by Hunt-Muckenhoupt-Wheeden…

Classical Analysis and ODEs · Mathematics 2010-11-29 Michael T Lacey

Let $R$ be the vector of Riesz transforms on $\mathbb{R}^n$, and let $\mu,\lambda \in A_p$ be two weights on $\mathbb{R}^n$, $1 < p < \infty$. The two-weight norm inequality for the commutator $[b, R] : L^p(\mathbb{R}^n;\mu) \to…

Classical Analysis and ODEs · Mathematics 2017-05-30 Irina Holmes , Michael T. Lacey , Brett D. Wick

Let $(X, \mathcal{A},\mu)$ be a probability space and let $T$ be a contraction on $L^2(\mu)$. We provide suitable conditions over sequences $(w_k)$, $(u_k)$ and $(A_k)$ in such a way that the weighted ergodic limit…

Dynamical Systems · Mathematics 2020-07-03 Ahmad Darwiche , Dominique Schneider

We establish a weighted inequality for the Bergman projection with matrix weights for a class of pseudoconvex domains. We extend a result of Aleman-Constantin and obtain the following estimate for the weighted norm of $P$:…

Complex Variables · Mathematics 2022-04-15 Zhenghui Huo , Brett D. Wick

For the Gegenbauer weight function $w_{\lambda}(t)=(1-t^2)^{\lambda-1/2}$, $\lambda>-1/2$, we denote by $\Vert\cdot\Vert_{w_{\lambda}}$ the associated $L_2$-norm, $$ \Vert…

Classical Analysis and ODEs · Mathematics 2017-02-21 Dragomir Aleksov , Geno Nikolov

We show that the norm of the vector of Riesz transforms as operator in the weighted Lebesgue space L^2(w) is bounded by a constant multiple of the first power of the Poisson-A_2 characteristic of w. The bound is free of dimension. Our…

Classical Analysis and ODEs · Mathematics 2016-12-13 Komla Domelevo , Stefanie Petermichl , Janine Wittwer

We construct an example showing that the upper bound $[w]_{A_1}\log({\rm{e}}+[w]_{A_1})$ for the $L^1(w)\to L^{1,\infty}(w)$ norm of the Hilbert transform cannot be improved in general.

Classical Analysis and ODEs · Mathematics 2020-09-16 Andrei K. Lerner , Fedor Nazarov , Sheldy Ombrosi

Given p between 1 and infinity, but not 2, we show that the T1 theorem for the Hilbert transform fails for L^{p}, despite holding for p equal to 2

Functional Analysis · Mathematics 2024-03-05 Michel Alexis , Jose Luis Luna-Garcia , Eric T. Sawyer , Ignacio Uriarte-Tuero

In this paper the W-algebra W(2,2) and its representation theory are studied. It is proved that a simple vertex operator algebra generated by two weight 2 vectors is either a vertex operator algebra associated to a highest irreducible…

Quantum Algebra · Mathematics 2007-11-30 W. Zhang , C. Dong

We investigate the unconditional basis property of martingale differences in weighted $L^2$ spaces in the non-homogeneous situation (i.e. when the reference measure is not doubling). Specifically, we prove that finiteness of the quantity…

Analysis of PDEs · Mathematics 2014-11-20 C. Thiele , S. Treil , A. Volberg

We show sufficient conditions on matrix weights $U$ and $V$ for the martingale transforms to be uniformly bounded from $L^2(V)$ to $L^2(U)$. We also show that these conditions imply the uniform boundedness of the dyadic shifts as well as…

Classical Analysis and ODEs · Mathematics 2010-06-24 Robert Kerr

We use the Bellman function method to give an elementary proof of a sharp weighted estimate for the Haar shifts, which is linear in the $A_2$ norm of the weight and in the complexity of the shift. Together with the representation of a…

Classical Analysis and ODEs · Mathematics 2011-05-12 Sergei Treil

We prove generalized Carleson embeddings for the continuous wave packet transform from $L^p(\mathbb{R},w)$ into an outer $L^p$ space for $2< p < \infty$ and weight $w \in A_{p/2}$. This work is a weighted extension of the corresponding…

Classical Analysis and ODEs · Mathematics 2020-07-29 Yen Do , Mark Lewers