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Related papers: Inner functions and zero sets for $\ell^{p}_{A}$

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We use shift-invariant subspaces of the Hardy space on the bidisk to provide an elementary proof of the Agler Decomposition Theorem. We observe that these shift-invariant subspaces are specific cases of Hilbert spaces that can be defined…

Functional Analysis · Mathematics 2017-01-20 Kelly Bickel

The tetrablock is the set $$ \mathcal{E}=\{x \in \mathbb{C}^3: \quad 1-x_1z-x_2w+x_3z w \neq 0 \quad whenever \quad |z|\leq 1, |w|\leq 1\}. $$ The closure of $\mathcal{E}$ is denoted by $\overline{\mathcal{E}}$. A tetra-inner function is an…

Complex Variables · Mathematics 2021-01-08 Hadi O. Alshammari , Zinaida A. Lykova

Among the sets of sequences studied, difference sets of sequences are probably the most common type of sets. This paper considers some $\ell_{p}$ type fractional difference sequence spaces via Euler gamma function. Although we characterize…

Functional Analysis · Mathematics 2018-02-13 Faruk Özger

Let $B$ be a Blaschke product with zeros $\{a_n\}$. If $B' \in A^p_{\alpha}$ for certain $p$ and $\alpha$, it is shown that $\sum_n (1 - |a_n|)^{\beta} < \infty$ for appropriate values of $\beta$. Also, if $\{a_n\}$ is uniformly discrete…

Complex Variables · Mathematics 2010-09-29 David Protas

We use properties of the sequences of zeros of certain spaces of analytic functions in the unit disc $\mathbb D$ to study the question of characterizing the weighted superposition operators which map one of these spaces into another. We…

Complex Variables · Mathematics 2019-10-29 Salvador Domínguez , Daniel Girela

Let $A$ be a Banach space, $p>1$, and $1/p+1/q=1$. If a sequence $a=(a_i)$ in $A$ has a finite $p$-sum, then the operator $\Lambda_a:\ell^q\to A$, defined by $\Lambda_a(\beta)=\sum_{i=1}^\infty \beta_i a_i, \beta=(\beta_i)\in \ell^q$, is…

Functional Analysis · Mathematics 2025-06-10 Mortaza Abtahi

By generalizing the classical Selberg-Chowla formula, we establish the analytic continuation and functional equation for a large class of Epstein zeta functions. This continuation is studied in order to provide new classes of theorems…

Number Theory · Mathematics 2022-02-25 Pedro Ribeiro , Semyon Yakubovich

For $0<p<\infty $ and $\alpha >-1$ the space of Dirichlet type $\mathcal D^p_\alpha $ consists of those functions $f$ which are analytic in the unit disc $\mathbb D$ and satisfy $\int_{\mathbb D}(1-| z| )^\alpha| f^\prime (z)|…

Complex Variables · Mathematics 2018-04-12 Petros Galanopoulos , Daniel Girela , María Auxiliadora Márquez

We study $H^p$ spaces of Dirichlet series, called $\mathcal{H}^p$, for the range $0<p< \infty$. We begin by showing that two natural ways to define $\mathcal{H}^p$ coincide. We then proceed to study some linear space properties of…

Functional Analysis · Mathematics 2019-09-05 Andriy Bondarenko , Ole Fredrik Brevig , Eero Saksman , Kristian Seip

Let $E$ be a closed set on the unit circle. We find a Blaschke-type condition, optimal in a sense of the order, on the Riesz measure of a subharmonic function $v$ in the unit disk with a certain growth at the direction of $E$. In particular…

Complex Variables · Mathematics 2009-06-27 S. Favorov , L. Golinskii

The purpose of this note is to show that the set functions defined in \cite{trong-tuyen} can be suitably extended to all subsets $E$ of the unit disk $\mathbb{D}$. In particular we obtain uniform nearly-optimal estimates for the following…

Complex Variables · Mathematics 2008-12-02 Tuyen Trung Truong

Matrix valued inner functions on the bidisk have a number of natural subspaces of the Hardy space on the torus associated to them. We study their relationship to Agler decompositions, regularity up to the boundary, and restriction maps into…

Functional Analysis · Mathematics 2017-01-20 Kelly Bickel , Greg Knese

To address the uniqueness issues associated with the Dirichlet problem for the $N$-harmonic equation on the unit disk $\D$ in the plane, we investigate the $L^p$ integrability of $N$-harmonic functions with respect to the standard weights…

Analysis of PDEs · Mathematics 2015-09-23 Alexander Borichev , Haakan Hedenmalm

Let $E$ be a closed subset of the unit circle of measure zero. Recently, Beise and M\"uller showed the existence of a function in the Hardy space $H^2$ for which the partial sums of its Taylor series approximate any continuous function on…

Complex Variables · Mathematics 2019-05-21 Catherine Bénéteau , Oleg Ivrii , Myrto Manolaki , Daniel Seco

The study of inner and cyclic functions in $\ell^p_A$ spaces requires a better understanding of the zeros of the so-called optimal polynomial approximants. We determine that a point of the complex plane is the zero of an optimal polynomial…

Complex Variables · Mathematics 2021-04-19 Raymond Cheng , William T. Ross , Daniel Seco

If $g$ is an analytic function in the unit disc $\D $ we consider the generalized Hilbert operator $\hg$ defined by {equation*}\label{H-g} \mathcal{H}_g(f)(z)=\int_0^1f(t)g'(tz)\,dt. {equation*} We study these operators acting on classical…

Complex Variables · Mathematics 2018-04-12 Petros Galanopoulos , Daniel Girela , José Ángel Peláez , Aristomenis Siskakis

In this article we address the question of characterizing the sequences of complex numbers $(\eta )=\{ \eta_n\}_{n=0}^\infty $ whose associated Rhaly operator $\mathcal R_{(\eta )}$ is bounded or compact on the Hardy spaces $H^p$ ($1\le…

Complex Variables · Mathematics 2025-12-18 Petros Galanopoulos , Daniel Girela

Given a sequence = (r n) n $\in$ [0, 1) tending to 1, we consider the set U A (D,) of Abel universal series consisting of holomorphic functions f in the open unit disc D such that for any compact set K included in the unit circle T,…

Complex Variables · Mathematics 2022-09-14 S Charpentier , A Mouze

We prove existence and uniqueness of a solution of the Dirichlet problem for separately $(\alpha, \beta)$ - harmonic functions on the unit polydisc $\mathbb D^n$ with boundary data in $C(\mathbb T^n)$ using $(\alpha, \beta)$ - Poisson…

Complex Variables · Mathematics 2023-05-19 Jelena Gajic , Milos Arsenovic , Miodrag Mateljevic

The zero sets of the Bergman space $A^p_\omega$ induced by either a radial weight $\omega$ admitting a certain doubling property or a non-radial Bekoll\'e-Bonami type weight are characterized in the spirit of Luecking's results from 1996.…

Complex Variables · Mathematics 2019-02-07 Taneli Korhonen , Jouni Rättyä