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

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Given the reproducing kernel $k$ of the Hilbert space $\mathcal{H}_k$ we study spaces $\mathcal{H}_k(b)$ whose reproducing kernel has the form $k(1-bb^*)$, where $b$ is a row-contraction on $\mathcal{H}_k$. In terms of reproducing kernels…

Functional Analysis · Mathematics 2024-12-17 Alexandru Aleman , Frej Dahlin

Let $\mathcal{H}(b)$ denote the de Branges--Rovnyak space associated with a function $b$ in the unit ball of $H^\infty(\mathbb{C}_+)$. We study the boundary behavior of the derivatives of functions in $\mathcal{H}(b)$ and obtain weighted…

Complex Variables · Mathematics 2008-02-07 Anton Baranov , Emmanuel Fricain , Javad Mashreghi

This work is devoted to the comparison of de Branges--Rovnyak $H(b)$ spaces harmonically weighted Dirichlet spaces $\mathcal{D}_\mu$. We completely characterize which $H(b)$ spaces are also harmonically weighted Dirichlet spaces…

Functional Analysis · Mathematics 2025-05-27 Eugenio Dellepiane , Marco M. Peloso , Anita Tabacco

In this paper, we give an integral representation for the boundary values of derivatives of functions of the de Branges--Rovnyak spaces $\HH(b)$, where $b$ is in the unit ball of $H^\infty(\CC_+)$. In particular, we generalize a result of…

Complex Variables · Mathematics 2008-02-07 Emmanuel Fricain , Javad Mashreghi

Motivated by the recent developments of de Branges-Rovnyak spaces, we investigate the function theoretic aspects of finite rank de Branges-Rovnyak spaces $H(B)$ generated by row-valued Schur functions $B$. We provide a generalization of…

Functional Analysis · Mathematics 2026-05-19 Soumitra Ghara , MD Ramiz Reza , Chaman Kumar Sahu

Let $B_n$ denote the unit ball of $\mathbb{C}^n$, $n\ge 1$, and let $\mathcal{D}$ denote a finite product of $B_{n_j}$, $j\ge 1$. Given a non-constant holomorphic function $b: \mathcal{D} \to B_1$, we study the corresponding family…

Complex Variables · Mathematics 2021-08-20 Aleksei B. Aleksandrov , Evgueni Doubtsov

In this work we study deBranges-Rovnyak spaces, $H(b)$, on the unit ball of $\mathbb{C}^n$. We give an integral representation of the functions in $H(b)$ through the Clark measure on $S^n$ associated with $b$. A characterization of…

Complex Variables · Mathematics 2019-09-18 Sibel Sahin

For $S$ a contractive analytic operator-valued function on the unit disk ${\mathbb D}$, de Branges and Rovnyak associate a Hilbert space of analytic functions ${\mathcal H}(S)$ and related extension space ${\mathcal D(S)}$ consisting of…

Classical Analysis and ODEs · Mathematics 2014-05-14 Joseph A. Ball , Vladimir Bolotnikov

For $S$ a contractive analytic operator-valued function on the unit disk ${\mathbb D}$, de Branges and Rovnyak associate a Hilbert space of analytic functions ${\mathcal H}(S)$. A companion survey provides equivalent definitions and basic…

Classical Analysis and ODEs · Mathematics 2014-05-14 Joseph A. Ball , Vladimir Bolotnikov

A general interpolation problem with operator argument is studied for functions f from the de Branges-Rovnyak space H(s) associated with an analytic function s mapping the open unit disk D into the closed unit disk. The interpolation…

Functional Analysis · Mathematics 2018-04-24 Joseph A. Ball , Vladimir Bolotnikov , Sanne Ter Horst

We investigate expansive Hilbert space operators $T$ that are finite rank perturbations of isometric operators. If the spectrum of $T$ is contained in the closed unit disc $\overline{\mathbb{D}}$, then such operators are of the form $T=…

Functional Analysis · Mathematics 2020-09-01 Shuaibing Luo , Caixing Gu , Stefan Richter

Using the notion of commutative operator vessels, this work investigates de Branges-Rovnyak spaces whose elements are sections of a line bundle of multiplicative half-order differentials on a compact real Riemann surface. As a special case,…

Complex Variables · Mathematics 2020-07-15 Daniel Alpay , Ariel Pinhas , Victor Vinnikov

We show that de Branges-Rovnyak spaces include as special cases a number of spaces, such as the Hardy space, the Fock space, the Hardy-Sobolev space and the Dirichlet space. We present a general framework in which all these spaces can be…

Functional Analysis · Mathematics 2018-12-19 Daniel Alpay , Fabrizio Colombo , Irene Sabadini

We study a general metric constrained interpolation problem in a de Branges-Rovnyak space $\mathcal{H}(K_S)$ associated with a contractive multiplier $S$ between two Fock spaces along with its commutative counterpart, a de Branges-Rovnyak…

Functional Analysis · Mathematics 2022-05-23 Joseph A. Ball , Vladimir Bolotnikov , Sanne ter Horst

We study de Branges--Rovnyak spaces parametrized by L\"{o}wner equations. A new approach based on the L\"{o}wner theory to problem ``Find concrete elements in de Branges--Rovnyak spaces'' is given.

Functional Analysis · Mathematics 2026-01-08 Michio Seto

We establish a connection between the de Branges-Rovnyak spaces and the Cowen-Douglas class of operators which is associated with complex geometric structures. We prove that the backward shift operator on a de Branges-Rovnyak space never…

Functional Analysis · Mathematics 2025-04-08 Emmanuel Fricain , Jaydeb Sarkar

Relations between two classes of Hilbert spaces of entire functions, de Branges spaces and Fock-type spaces with non-radial weights, are studied. It is shown that any de Branges space can be realized as a Fock-type space with equivalent…

Complex Variables · Mathematics 2018-01-08 Anton Baranov , Hélène Bommier-Hato

In this paper, we study the cyclic vectors of the shift operator $S_b$ acting on de Branges-Rovnyak space $\mathcal H(b)$ associated to a non-extreme point of the closed unit ball of $H^\infty$. We highlight an interesting link with a…

Complex Variables · Mathematics 2024-03-08 Emmanuel Fricain , Romain Lebreton

Let $H^p=H^p(B_d)$ denote the Hardy space in the open unit ball $B_d$ of $\mathbb{C}^d$, $d\ge 1$. We characterize the reverse Carleson measures for $H^p$, $1<p<\infty$, that is, we describe all finite positive Borel measures $\mu$, defined…

Complex Variables · Mathematics 2023-08-30 Evgueni Doubtsov

For $1/2<p<1$, a description of inner functions whose derivative is in the Hardy space $H^p$ is given in terms of either their mapping properties or the geometric distribution of their zeros.

Complex Variables · Mathematics 2018-10-01 Janne Gröhn , Artur Nicolau