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Related papers: New estimates for the maximal singular integral

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In this paper we study harmonic analysis operators in Dunkl settings associated with finite reflection groups on Euclidean spaces. We consider maximal operators, Littlewood-Paley functions, $\rho$-variation and oscillation operators…

Classical Analysis and ODEs · Mathematics 2023-09-13 Víctor Almeida , Jorge J. Betancor , Juan C. Fariña , Lourdes Rodríguez-Mesa

We consider compact Hankel operators realized in $\ell^2(\mathbb Z_+)$ as infinite matrices $\Gamma$ with matrix elements $h(j+k)$. Roughly speaking, we show that, for all $\alpha>0$, the singular values $s_{n}$ of $\Gamma$ satisfy the…

Spectral Theory · Mathematics 2014-12-02 Alexander Pushnitski , Dmitri Yafaev

We provide a complete set of supersymmetric constraints for the anomalous dimensions of the conformal twist-two operators to all orders of perturbation theory. Employing them we derive new relations between the exclusive evolution kernels…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. V. Belitsky , D. Müller

We consider a self-adjoint non-negative operator $H$ in a Hilbert space $\mathsf{L}^2(X,{\rm d}\mu)$. We assume that the semigroup $(\mathrm{e}^{-t H})_{t>0}$ is defined by an integral kernel, $p$, which allows an estimate of the form…

Spectral Theory · Mathematics 2016-06-03 Jochen Brüning , Batu Güneysu

In this paper, we establish some bilinear endpoint estimates of Calder\'on commutator $\mathcal{C}[\nabla A,f](x)$ with a homogeneous kernel when $\Omega\in L\log^+L(\mathbf{S}^{d-1})$. More precisely, we prove that $\mathcal{C}[\nabla…

Classical Analysis and ODEs · Mathematics 2017-10-27 Xudong Lai

We prove that in any metric space $(X,d)$ the singular integral operators {equation*} T^k_{\mu,\ve}(f)(x)=\int_{X\setminus B(x,\varepsilon)}k(x,y)f(y)d\mu (y).{equation*} converge weakly in some dense subspaces of $L^2(\mu)$ under minimal…

Classical Analysis and ODEs · Mathematics 2016-10-17 Vasilis Chousionis , Mariusz Urbański

In this paper we study sharp pointwise inequalities for maximal operators. In particular, we strengthen DeVore's inequality for the moduli of smoothness and a logarithmic variant of Bennett--DeVore--Sharpley's inequality for rearrangements.…

Functional Analysis · Mathematics 2021-02-10 Oscar Domínguez , Sergey Tikhonov

As a step in developing a non-commutative Calderon-Zygmund theory, J. Parcet (J. Funct. Anal., 2009) established a new pseudo-localisation principle for classical singular integrals, showing that Tf has small L^2 norm outside a set which…

Functional Analysis · Mathematics 2010-04-15 Tuomas P. Hytönen

Given a bounded Lipschitz domain $D\subset \mathbb{R}^d,$ a convolution Calder\'{o}n-Zygmund operator $T$ and a growth function $\omega(x)$ of type $n$, we study what conditions on the boundary of the domain are sufficient for boundedness…

Functional Analysis · Mathematics 2023-10-31 Andrei Vasin

In this work, we establish $L^{p_1}\times \cdots\times L^{p_m}\to L^p$ bounds for maximal multi-(sub)linear singular integrals associated with homogeneous kernels $\frac{\Omega(\vec{\boldsymbol{y}}')}{|\vec{\boldsymbol{y}}|^{mn}}$ where…

Classical Analysis and ODEs · Mathematics 2025-03-18 Bae Jun Park

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

In this work, we present a bilinear Tb theorem for singular integral operators of Calder\'on-Zygmund type. We prove some new accretive type Littlewood-Paley theory and bilinear paraproduct for a para-accretive function setting. We also…

Functional Analysis · Mathematics 2015-02-24 Jarod Hart

In this paper, we study the optimal control problem with terminal and inequality state constraints for state equations described by Volterra integral equations having singular and nonsingular kernels. The singular kernel introduces abnormal…

Optimization and Control · Mathematics 2022-06-09 Jun Moon

The purpose of this announcement is to describe a development given in a series of forthcoming papers by the authors that concern operators of the form \[ f\mapsto \psi(x) \int f(\gamma_t(x)) K(t)\: dt, \] where $\gamma_t(x)=\gamma(t,x)$ is…

Classical Analysis and ODEs · Mathematics 2011-01-27 Elias M. Stein , Brian Street

Let $\T (0\leq \alpha <n)$ be the singular and fractional integrals with variable kernel $\Omega(x,z)$, and $[b,\T]$ be the commutator generated by $\T$ and a Lipschitz function $b$. In this paper, the authors study the boundedness of…

Classical Analysis and ODEs · Mathematics 2007-05-23 Pu Zhang , Kai Zhao

The regularity of integration kernels forces decay rates of singular values of associated integral operators. This is well-known for symmetric operators with kernels defined on $(a,b) \times (a,b)$, where $(a,b)$ is an interval. Over time,…

Functional Analysis · Mathematics 2023-11-07 Darko Volkov

Let $({\mathcal X}, d, \mu)$ be a separable metric measure space satisfying the known upper doubling condition, the geometrical doubling condition and the non-atomic condition that $\mu(\{x\})=0$ for all $x\in{\mathcal X}$. In this paper,…

Classical Analysis and ODEs · Mathematics 2010-12-20 Tuomas Hytönen , Suile Liu , Dachun Yang , Dongyong Yang

In this note, we show that if $T$ is a Calder\'on--Zygmund operator satisfying $T(1)=0$, then the usual sparse domination for $T$ can be sharpened by replacing local averages by local mean oscillations. As an application, we characterize…

Classical Analysis and ODEs · Mathematics 2026-05-27 Andrei K. Lerner

We study the two-weighted off-diagonal compactness of commutators of rough singular integral operators $T_\Omega$ that are associated with a kernel $\Omega\in L^q(\mathbb{S}^{d-1})$. We establish a characterisation of compactness of the…

Classical Analysis and ODEs · Mathematics 2025-03-17 Aapo Laukkarinen , Jaakko Sinko

Calder\'on-Zygmund decompositions of functions have been used to prove weak-type (1,1) boundedness of singular integral operators. In many examples, the decomposition is done with respect to a family of balls that corresponds to some family…

Classical Analysis and ODEs · Mathematics 2012-08-15 H. F. Bloch