English
Related papers

Related papers: Concrete examples of $\mathscr{H}(b)$ spaces

200 papers

A description of the Bloch functions that can be approximated in the Bloch norm by functions in the Hardy space $H^p$ of the unit ball of $\Cn$ for $0<p<\infty$ is given. When $0<p\leq1$, the result is new even in the case of the unit disk.

Complex Variables · Mathematics 2014-08-21 Petros Galanopoulos , Nacho Monreal Galán , Jordi Pau

We introduce and study a Fock-space noncommutative analogue of reproducing kernel Hilbert spaces of de Branges-Rovnyak type. Results include: use of the de Branges-Rovnyak space ${\mathcal H}(K_{S})$ as the state space for the unique (up to…

Classical Analysis and ODEs · Mathematics 2007-05-23 Joseph A. Ball , Vladimir Bolotnikov , Quanlei Fang

We prove that functions continuous up to the boundary are dense in de Branges-Rovnyak spaces induced by extreme points the unit ball of $H^\infty$.

Functional Analysis · Mathematics 2017-04-07 Alexandru Aleman , Bartosz Malman

We study the compactness and the hypercyclicity of Toeplitz operators in the de Branges-Rovnyak spaces H(b) with co-analytic and bounded symbols on D. We highlight the fundamental role played by the function b generating the de…

Functional Analysis · Mathematics 2018-12-19 Rim Alhajj

In this article, methods from sub-Hardy Hilbert spaces such as the de Branges-Rovnyak spaces and local Dirichlet spaces are used to investigate B\'aez-Duarte's Hilbert space reformulation of the Riemann hypothesis (RH).

Functional Analysis · Mathematics 2019-05-10 S. Waleed Noor

In this paper we study embeddings between de Branges-Rovnyak spaces $H(b)$ and harmonically weighted Dirichlet spaces $\mathcal{D}(\mu)$ in terms of the boundary spectrum of $b$ and the support of the measure $\mu$, by using elementary…

Functional Analysis · Mathematics 2023-12-13 Carlo Bellavita , Eugenio Alberto Dellepiane

For positive integers d, r, and M, we consider the class of rational functions on real d-dimensional space whose denominators are products of at most r functions of the form 1+Q(x) where each Q is a quadratic form with eigenvalues bounded…

Functional Analysis · Mathematics 2007-09-18 R. M. Dudley , Sergiy Sidenko , Zuoqin Wang , Fangyun Yang

A rational function belongs to the Hardy space, $H^2$, of square-summable power series if and only if it is bounded in the complex unit disk. Any such rational function is necessarily analytic in a disk of radius greater than one. The…

Functional Analysis · Mathematics 2020-10-15 Michael T. Jury , Robert T. W. Martin , Eli Shamovich

We give a controllable energy-preserving and an observable co-energy-preserving de Branges-Rovnyak functional model realization of an arbitrary given operator Schur function defined on the complex right-half plane. We work the theory out…

Optimization and Control · Mathematics 2015-11-09 Joseph A. Ball , Mikael Kurula , Olof J. Staffans , Hans Zwart

We introduce the notion of rationality for hyperholomorphic functions (functions in the kernel of the Cauchy-Fueter operator). Following the case of one complex variable, we give three equivalent definitions: the first in terms of…

Functional Analysis · Mathematics 2007-05-23 D. Alpay , M. Shapiro , D. Volok

Given a continuous, radial, rapidly decreasing weight $v$ on the complex plane $\mathbf{C}$, we study the solid hull of its associated weighted space $H_v^\infty(\mathbf{C})$ of all the entire functions $f$ such that $v|f|$ is bounded. The…

Functional Analysis · Mathematics 2016-07-11 José Bonet , Jari Taskinen

In this paper we begin the study of Schur analysis and de Branges-Rovnyak spaces in the framework of Fueter hyperholomorphic functions. The difference with other approaches is that we consider the class of functions spanned by Appell-like…

Functional Analysis · Mathematics 2021-08-03 Daniel Alpay , Fabrizio Colombo , Kamal Diki , Irene Sabadini

We study reproducing kernel Hilbert and Pontryagin spaces of slice hyperholomorphic functions which are analogs of the Hilbert spaces of analytic functions introduced by de Branges and Rovnyak. In the first part of the paper we focus on the…

Functional Analysis · Mathematics 2012-03-02 Daniel Alpay , Fabrizio Colombo , Irene Sabadini

In this paper we consider the Hardy-Lorentz spaces $H^{p,q}(R^n)$, with $0<p\le 1$, $0<q\le \infty$. We discuss the atomic decomposition of the elements in these spaces, their interpolation properties, and the behavior of singular integrals…

Classical Analysis and ODEs · Mathematics 2013-10-15 Wael Abu-Shammala , Alberto Torchinsky

Let $X$ be a ball quasi-Banach function space, $\alpha\in \mathbb{R}$ and $q\in(0,\infty)$. In this paper, the authors first introduce the Herz-type Hardy space $\mathcal{H\dot{K}}_{X}^{\alpha,\,q}({\mathbb {R}}^n)$, which is defined via…

Functional Analysis · Mathematics 2025-06-10 Aiting Wang , Wenhua Wang , Mingquan Wei , Baode Li

We study properties of inner and outer functions in the Hardy space of the quaternionic unit ball. In particular, we give sufficient conditions as well as necessary ones for functions to be inner or outer.

Complex Variables · Mathematics 2019-03-06 Alessandro Monguzzi , Giulia Sarfatti , Daniel Seco

Let $M$ be a complete connected Riemannian manifold. Assuming that the Riemannian measure is doubling, we define Hardy spaces $H^p$ of differential forms on $M$ and give various characterizations of them, including an atomic decomposition.…

Differential Geometry · Mathematics 2007-05-23 Pascal Auscher , Alan Mcintosh , Emmanuel Russ

We apply the theory of de Branges-Rovnyak spaces to describe kernels of some Toeplitz operators on the classical Hardy space $H^2$. In particular, we discuss the kernels of the operators $T_{\bar f/ f}$ and $T_{\bar I\bar f/ f}$, where $f$…

Functional Analysis · Mathematics 2020-03-02 Maria T. Nowak , Paweł Sobolewski , Andrzej Sołtysiak , Magdalena Wołoszkiewicz-Cyll

We introduce connections between the Cuntz relations and the Hardy space H_2 of the open unit disk . We then use them to solve a new kind of multipoint interpolation problem in H_2, where for instance, only a linear combination of the…

Functional Analysis · Mathematics 2013-01-21 Daniel Alpay , Palle Jorgensen , Izchak Lewkowicz , Itzik Martziano

We prove that the norm of a weighted composition operator on the Hardy space H^2 of the disk is controlled by the norm of the weight function in the de Branges-Rovnyak space associated to the symbol of the composition operator. As a…

Functional Analysis · Mathematics 2007-07-24 Michael T. Jury