English
Related papers

Related papers: Contractively included subspaces of Pick spaces

200 papers

We prove a factorization theorem for reproducing kernel Hilbert spaces whose kernel has a normalized complete Nevanlinna-Pick factor. This result relates the functions in the original space to pointwise multipliers determined by the…

Functional Analysis · Mathematics 2018-07-19 Alexandru Aleman , Michael Hartz , John E. McCarthy , Stefan Richter

Let $\mathcal H$ be the Drury-Arveson or Dirichlet space of the unit ball of $\mathbb C^d$. The weak product $\mathcal H\odot\mathcal H$ of $\mathcal H$ is the collection of all functions $h$ that can be written as $h=\sum_{n=1}^\infty f_n…

Functional Analysis · Mathematics 2020-09-23 Alexandru Aleman , Michael Hartz , John E. McCarthy , Stefan Richter

We present an exposition of contractive spaces and of relatively contractive maps. Contractive spaces are the natural opposite of measure-preserving actions and relatively contractive maps the natural opposite of relatively…

Dynamical Systems · Mathematics 2016-03-29 Darren Creutz

Some fixed point results are given for a class of functional contractions acting on (reflexive) triangular symmetric spaces. Technical connections with the corresponding theories over (standard) metric and partial metric spaces are also…

General Topology · Mathematics 2013-11-01 Mihai Turinici

The present paper has a twofold contribution: first, we introduce a new concept of Hardy spaces on a multidimensional complexified annular domain which is closely related to the annulus of the Klein-Dirac quadric important in Conformal…

Numerical Analysis · Mathematics 2012-04-05 Ognyan Kounchev , Hermann Render

We define combinatorial counterparts to the geometric string vertices of Sen-Zwiebach and Costello-Zwiebach, which are certain closed subsets of the moduli spaces of curves. Our combinatorial vertices contain the same information as the…

Algebraic Topology · Mathematics 2020-09-16 Andrei Caldararu , Kevin Costello , Junwu Tu

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 revisit the construction of the Hilbert space of non-relativistic particles moving in three spatial dimensions. This is given by the space of sections of a line bundle that can in general be topologically non-trivial. Such bundles are…

High Energy Physics - Theory · Physics 2024-04-04 Rishi Mouland , David Tong

We characterize the reproducing kernel Hilbert spaces whose elements are $p$-integrable functions in terms of the boundedness of the integral operator whose kernel is the reproducing kernel. Moreover, for $p=2$ we show that the spectral…

Functional Analysis · Mathematics 2007-05-23 Claudio Carmeli , Ernesto De Vito , Alessandro Toigo

This paper defines local weighted Hardy spaces with variable exponent. Local Hardy spaces permit atomic decomposition, which is one of the main themes in this paper. A consequence is that the atomic decomposition is obtained for the…

Functional Analysis · Mathematics 2022-06-14 Mitsuo Izuki , Toru Nogayama , Takahiro Noi , Yoshihiro Sawano

We consider three problems connected with coinvariant subspaces of the backward shift operator in Hardy spaces $H^p$: 1) properties of truncated Toeplitz operators; 2) Carleson-type embedding theorems for the coinvariant subspaces; 3)…

Functional Analysis · Mathematics 2022-02-28 Anton Baranov , Roman Bessonov , Vladimir Kapustin

A unitarily invariant, complete Nevanlinna--Pick kernel $K$ on the unit ball determines a class of operators on Hilbert space called $K$-contractions. We study those $K$-contractions that are constrained, in the sense that they are…

Functional Analysis · Mathematics 2019-11-12 Raphaël Clouâtre , Edward J. Timko

We study the relationship between sampling sequences in infinite dimensional Hilbert spaces of analytic functions and Marcinkiewicz-Zygmund inequalities in subspaces of polynomials. We focus on the study of the Hardy space and the Bergman…

Complex Variables · Mathematics 2023-04-18 Karlheinz Gröchenig , Joaquim Ortega-Cerdà

We introduce generalized Schur functions and generalized positive functions in setting of slice hyperholomorphic functions and study their realizations in terms of associated reproducing kernel Pontryagin spaces

Complex Variables · Mathematics 2014-11-10 Daniel Alpay , Fabrizio Colombo , Izchak Lewkowicz , Irene Sabadini

We consider the mixed norm spaces of Hardy type studied by Flett and others. We study some properties of these spaces related to mean and pointwise growth and complement some partial results by various authors by giving a complete…

Complex Variables · Mathematics 2015-06-25 Irina Arévalo

This note contributes to a circle of ideas that we have been developing recently in which we view certain abstract operator algebras $H^{\infty}(E)$, which we call Hardy algebras, and which are noncommutative generalizations of classical…

Operator Algebras · Mathematics 2007-07-13 Paul S. Muhly , Baruch Solel

In the authors' first paper, Beurling-Rudin-Korenbljum type characterization of the closed ideals in a certain algebra of holomorphic functions was used to describe the lattice of invariant subspaces of the shift plus a complex Volterra…

Complex Variables · Mathematics 2018-02-27 Bhupendra Paudyal , Zeljko Cuckovic

Universal kernels, whose Reproducing Kernel Hilbert Space is dense in the space of continuous functions are of great practical and theoretical interest. In this paper, we introduce an explicit construction of universal kernels on compact…

Functional Analysis · Mathematics 2025-10-09 Eloi Tanguy

Let $\A$ be a finite subdiagonal algebra in Arveson's sense. Let $H^p(\A)$ be the associated noncommutative Hardy spaces, $0<p\le\8$. We extend to the case of all positive indices most recent results about these spaces, which include…

Operator Algebras · Mathematics 2007-05-23 Turdebek N. Bekjan , Quanhua Xu

In this article we will give a affirmative answer to Gilbert's conjecture on Hardy spaces of Clifford analytic functions in upper half-space of $\mathbb{R}^8$. It depends on a explicit construction of Spinor space $\mathcal{R}_8$ and…

Complex Variables · Mathematics 2024-05-15 Yong Li