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We give a complete characterization of polynomials in two complex variables that are cyclic with respect to the coordinate shifts acting on Dirichlet-type spaces in the bidisk, which include the Hardy space and the Dirichlet space of the…

Functional Analysis · Mathematics 2016-10-10 Catherine Bénéteau , Greg Knese , Łukasz Kosiński , Constanze Liaw , Daniel Seco , Alan Sola

Let $\cD$ be the Dirichlet space, namely the space of holomorphic functions on the unit disk whose derivative is square-integrable. We establish a new sufficient condition for a function $f\in\cD$ to be {\em cyclic}, i.e. for $\{pf:…

Complex Variables · Mathematics 2008-09-29 Omar El-Fallah , Karim Kellay , Thomas Ransford

We study Dirichlet-type spaces $\mathfrak{D}_{\alpha}$ of analytic functions in the unit bidisk and their cyclic elements. These are the functions $f$ for which there exists a sequence $(p_n)_{n=1}^{\infty}$ of polynomials in two variables…

Functional Analysis · Mathematics 2015-07-03 Catherine Bénéteau , Alberto A. Condori , Constanze Liaw , Daniel Seco , Alan A. Sola

We show the existence of singular inner functions that are cyclic in some Besov-type spaces of analytic functions over the unit disc. Our sufficient condition is stated only in terms of the modulus of smoothness of the underlying measure.…

Complex Variables · Mathematics 2025-11-11 Alberto Dayan , Daniel Seco

We study the invariant subspaces generated by inner functions for a class of $\mathcal{P}^t(\mu)$-spaces which can be identified as spaces of analytic functions in the unit disk $\mathbb{D}$, where $\mu$ is a measure supported in the closed…

Functional Analysis · Mathematics 2021-08-23 Adem Limani , Bartosz Malman

For spaces of analytic functions defined on an open set in $\mathbb{C}^n$ that satisfy certain nice properties, we show that operators that preserve shift-cyclic functions are necessarily weighted composition operators. Examples of spaces…

Complex Variables · Mathematics 2025-04-23 Jeet Sampat

We prove that a random function in the Hardy space $H^2$ is a non-cyclic vector for the backward shift operator almost surely. The question of existence of a local pseudocontinuation for a random analytic function is also studied.

Complex Variables · Mathematics 2007-05-23 Evgeny Abakumov , Alexei Poltoratski

We define the Hardy spaces of free noncommutative functions on the noncommutative polydisc and the noncommutative ball and study their basic properties. Our technique combines the general methods of noncommutative function theory and…

Operator Algebras · Mathematics 2017-05-26 Mihai Popa , Victor Vinnikov

We introduce new quantitative measures for cyclicity in radially weighted Besov spaces, including the Drury-Arveson space, by defining cyclicity indices based on potential theory and capacity. Extensions to non-commutative settings are…

Functional Analysis · Mathematics 2025-04-29 Saeed Hashemi Sababe , Amir Baghban

In this survey, we consider Banach spaces of analytic functions in one and several complex variables for which: (i) polynomials are dense, (ii) point-evaluations on the domain are bounded linear functionals, and (iii) the shift operator…

Functional Analysis · Mathematics 2025-04-23 Jeet Sampat

Let $\mathcal{H}$ be a space of analytic functions on the unit ball $\mathbb B_d$ in $\mathbb C^d$ with multiplier algebra $\mathrm{Mult}(\mathcal{H})$. A function $f\in \mathcal{H}$ is called cyclic if the set $[f]$, the closure of…

Functional Analysis · Mathematics 2023-01-13 Alexandru Aleman , Karl-Mikael Perfekt , Stefan Richter , Carl Sundberg , James Sunkes

Let $H^2_d$ be the Drury-Arveson space, and let $f\in H^2_d$ have bounded argument and no zeros in $\mathbb{B}_d$. We show that $f$ is cyclic in $H^2_d$ if and only if $\log f$ belongs to the Pick-Smirnov class $N^+(H^2_d)$. Furthermore,…

Functional Analysis · Mathematics 2023-01-25 Alexandru Aleman , Karl-Mikael Perfekt , Stefan Richter , Carl Sundberg , James Sunkes

The classical criterion for compactness in Banach spaces of functions can be reformulated into a simple tightness condition in the time-frequency domain. This description preserves more explicitly the symmetry between time and frequency…

Functional Analysis · Mathematics 2007-05-23 Monika Dörfler , Hans G. Feichtinger , Karlheinz Gröchenig

We use a special version of the Corona Theorem in several variables, valid when all but one of the data functions are smooth, to generalize to the polydisc and to the ball results obtained by El Fallah, Kellay and Seip about cyclicity of…

Complex Variables · Mathematics 2018-12-06 Eric Amar , Pascal J. Thomas

We give a sufficient condition for a composition operator with positive characteristic to be compact on the Hardy space of Dirichlet series.

Functional Analysis · Mathematics 2024-02-21 Frédéric Bayart

Consider the Dirichlet-type space on the bidisk consisting of holomorphic functions $f(z_1,z_2):=\sum_{k,l\geq 0}a_{kl}z_1^kz_2^l$ such that $\sum_{k,l\geq 0}(k+1)^{\alpha_1} (l+1)^{\alpha_2}|a_{kl}|^2 <\infty.$ Here the parameters…

Complex Variables · Mathematics 2015-12-16 Greg Knese , Lukasz Kosinski , Thomas J. Ransford , Alan Sola

We give a necessary and sufficient condition for a measure $\mu$ in the closed unit disk to be a reverse Carleson measure for Hardy spaces. This extends a previous result of Lef\'evre, Li, Queff\'elec and Rodr\'{\i}guez-Piazza \cite{LLQR}.…

Complex Variables · Mathematics 2014-11-07 Andreas Hartmann , Xavier Massaneda , Artur Nicolau , Joaquim Ortega-Cerdà

We give a necessary and sufficient condition for a holomorphic self-map $\phi$ of the tridisc to induce a bounded composition operator on the associated Hardy space. This condition depends on the behaviour of the first and the second…

Functional Analysis · Mathematics 2023-12-06 Frédéric Bayart

We consider weak-star closed invariant subspaces of the shift operator in the classical Bloch space. We prove that any bounded analytic function decomposes into two factors, one which is cyclic and another one generating a proper shift…

Functional Analysis · Mathematics 2025-05-26 Adem Limani , Artur Nicolau

A radially weighted Besov space $H$ is a space of holomorphic functions on the unit ball $\mathbb{B}_d \subseteq \mathbb{C}^d$ whose $N$-th radial derivative is square integrable with respect to a given admissible radial measure. We write…

Functional Analysis · Mathematics 2026-05-06 Anusrika Datta , Stefan Richter
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