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Related papers: An estimate for narrow operators on $L^p([0, 1])$

200 papers

In the first part of the paper we prove that for $2 < p, r < \infty$ every operator $T: L_p \to \ell_r$ is narrow. This completes the list of sequence and function Lebesgue spaces $X$ with the property that every operator $T:L_p \to X$ is…

Functional Analysis · Mathematics 2012-11-21 V. Mykhaylyuk , M. Popov , B. Randrianantoanina , G. Schechtman

Approximation properties of the sampling-type quasi-projection operators $Q_j(f,\varphi, \widetilde{\varphi})$ for functions $f$ from anisotropic Besov spaces are studied. Error estimates in $L_p$-norm are obtained for a large class of…

Classical Analysis and ODEs · Mathematics 2020-01-27 Yurii Kolomoitsev , Maria Skopina

We obtain $L^p$ estimates for Toeplitz operators on the generalized Hartogs triangles $\mathbb{H}_\gamma = \{(z_1,z_2) \in \mathbb{C}^2: |z_1|^\gamma < |z_2|<1\}$ for two classes of positive radial symbols, one a power of the distance to…

Complex Variables · Mathematics 2023-10-18 Meijke Balay , Trent Neutgens , Nick Rosen , Nathan A. Wagner , Yunus E. Zeytuncu

We investigate the Hilbert transform and the maximal operator along a class of variable non-flat polynomial curves $(P(t),u(x)t)$ with measurable $u(x)$, and prove uniform $L^p$ estimates for $1<p<\infty$. In particular, via the change of…

Classical Analysis and ODEs · Mathematics 2023-06-01 Renhui Wan

In this paper, estimates for norms of weighted summation operators (discrete Hardy-type operators) on a tree are obtained for $1<p<q<\infty$ and for arbitrary weights and trees.

Classical Analysis and ODEs · Mathematics 2015-09-24 A. A. Vasil'eva

We generalize a classical result by A.Macintyre and W.Rogosinski on best $H^p$--approximation in $L^p$ of rational functions. For each inner function $\theta$ we give a description of $H^p$--badly approximable functions in $\bar \theta…

Complex Variables · Mathematics 2013-09-26 R. V. Bessonov

We prove uniform $L^p$ estimates for a family of paraproducts and corresponding maximal operators.

Classical Analysis and ODEs · Mathematics 2007-05-23 Camil Muscalu , Terence Tao , Christoph Thiele

We prove affirmatively the one dimensional case of a conjecture of Stein regarding the $L^p$-boundedness of the Polynomial Carleson operator, for $1<p<\infty$. The proof is based on two new ideas: i) developing a framework for…

Classical Analysis and ODEs · Mathematics 2019-02-12 Victor Lie

The classical Littlewood's theorem establishes boundedness and provides a norm estimate for composition operators on the Hardy space. In this paper, we offer an alternative proof of boundedness and derive a new norm estimate that improves…

Functional Analysis · Mathematics 2025-11-19 Preeti Kumari , P. Muthukumar , Jaydeb Sarkar

By a theorem of Bayart, $\varphi$ generates a bounded composition operator on the Hardy space $\Hp$of Dirichlet series ($1\le p<\infty$) only if $\varphi(s)=c_0 s+\psi(s)$, where $c_0$ is a nonnegative integer and $\psi$ a Dirichlet series…

Functional Analysis · Mathematics 2016-02-26 Frédéric Bayart , Hervé Queffélec , Kristian Seip

We prove $l^p$-improving estimates for the averaging operator along the discrete paraboloid in the sharp range of $p$ in all dimensions $n\ge 2$.

Classical Analysis and ODEs · Mathematics 2020-02-28 Shival Dasu , Ciprian Demeter , Bartosz Langowski

We introduce a noncommutative analogue of the absolute value of a regular operator acting on a noncommutative $\mathrm{L}^p$-space. We equally prove that two classical operator norms, the regular norm and the decomposable norm are…

Operator Algebras · Mathematics 2022-03-21 Cédric Arhancet , Christoph Kriegler

We prove the $L^p$-boundedness, $1<p<\infty$, of the Polynomial Carleson operator in general dimension. This follows the author's resolution of the one dimensional case as well as the work of Zorin-Kranich on the higher dimensional case in…

Classical Analysis and ODEs · Mathematics 2017-12-11 Victor Lie

We study the boundedness of the linear operator $S$ on $L^{p}_{a}(dA_{\alpha})$ $(0<p<\infty)$. In particular, we obtain a sufficient and necessary condition for the compactness of the linear operator $S$ on $L^{p}_{a}(dA_{\alpha})$…

Functional Analysis · Mathematics 2025-07-15 Zengjian Lou , Antti Rasila , Senhua Zhu

In this article we prove $L^p$ estimates for resolvents of Laplace-Beltrami operators on compact Riemannian manifolds, generalizing results of Kenig, Ruiz and Sogge in the Euclidean case and Shen for the torus. We follow Sogge and construct…

Analysis of PDEs · Mathematics 2011-12-15 David Dos Santos Ferreira , Carlos E. Kenig , Mikko Salo

New perspectives, proofs, and some extensions of known results are presented concerning the behavior of the Fitzpatrick function of a monotone type operator in the general context of a locally convex space.

Functional Analysis · Mathematics 2017-12-27 M. D. Voisei

Let $\Omega$ be a $C^4$-smooth bounded pseudoconvex domain in $\mathbb{C}^2$. We show that if the $\overline{\partial}$-Neumann operator $N_1$ is compact on $L^2_{(0,1)}(\Omega)$ then the embedding operator…

Complex Variables · Mathematics 2022-07-28 Sonmez Sahutoglu , Yunus E. Zeytuncu

We define a p-norm in the context of quantum random variables, measurable operator-valued functions with respect to a positive operator-valued measure. This norm leads to a operator-valued L^p space that is shown to be complete. Various…

Functional Analysis · Mathematics 2021-08-31 Christopher Ramsey , Adam Reeves

We introduce a new method to prove lower estimates for the approximation error of general linear operators with smooth range in terms of classical moduli of smoothness and related $K$-functionals. In addition, we explicitly show how to…

Classical Analysis and ODEs · Mathematics 2017-06-05 Johannes Nagler

The goal of this note is to give, at least for a restricted range of indices, a short proof of homogeneous commutator estimates for fractional derivatives of a product, using classical tools. Both $L^{p}$ and weighted $L^{p}$ estimates can…

Analysis of PDEs · Mathematics 2019-07-25 Piero D'Ancona