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Related papers: Cyclicity in de Branges--Rovnyak spaces

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We study the continuity, and dynamical properties (hypercyclicity, periodic vectors, and chaos) for a weighted backward shift $B_w$ on a weighted Bergman space $A^p_{\phi}$ based on the norm estimates of coefficient functionals on…

Functional Analysis · Mathematics 2025-11-19 Bibhash Kumar Das , Aneesh Mundayadan

In the deBranges-Rovnyak functional model for contractions on Hilbert space, any completely non-coisometric (CNC) contraction is represented as the adjoint of the restriction of the backward shift to a deBranges-Rovnyak space, $\mathscr{H}…

Functional Analysis · Mathematics 2019-01-23 R. T. W. Martin , A. Ramanantoanina

Let $\mathds{k}$ be a real quadratic number field. Denote by $\mathrm{Cl}_2(\mathds{k})$ its $2$-class group and by $\mathds{k}_2^{(1)}$ (resp. $\mathds{k}_2^{(2)}$) its first (resp. second) Hilbert $2$-class field. The aim of this paper is…

Number Theory · Mathematics 2023-06-22 A Azizi , M Rezzougui , A Zekhnini

In this paper, we answer a question posed in the introduction of \cite{sub hyp} positively, i.e, we show that if $T$ is $\mathcal M$-hypercyclic operator with $\mathcal M$-hypercyclic vector $x$ in a Hilbert space $\mathcal H$, then…

Functional Analysis · Mathematics 2014-06-05 Nareen Sabih , Adem Kılıçman

This paper explores various classes of invariant subspaces of the classical Ces\`{a}ro operator $C$ on the Hardy space $H^2$. We provide a new characterization of the finite co-dimensional $C$-invariant subspaces, based on earlier work of…

Functional Analysis · Mathematics 2023-11-28 Eva A. Gallardo-Gutierrez , Jonathan R. Partington , William T. Ross

According to Kim, Peris and Song, a continuous linear operator $T$ on a complex Banach space $X$ is called {\it numerically hypercyclic} if the numerical orbit $\{f(T^nx):n\in\N\}$ is dense in $\C$ for some $x\in X$ and $f\in X^*$…

Functional Analysis · Mathematics 2013-02-12 Stanislav Shkarin

A bounded linear operator T on Hilbert space is subspace-hypercyclic for a subspace M if there exists a vector whose orbit under T intersects the subspace in a relatively dense set. We construct examples to show that subspace-hypercyclicity…

Functional Analysis · Mathematics 2013-09-26 Blair Madore , Rubén A. Martínez Avendaño

In this paper we use the technique of premeasures, introduced by Korenblum in the 1970-s, to give a characterization of cyclic functions in the Korenblum type spaces $\mathcal{A}_{\Lambda}^{-\infty}$. In particular, we give a positive…

Functional Analysis · Mathematics 2013-05-16 Abdelouahab Hanine

We enrich the Lambek calculus with the cyclic shift operation, which is expected to model the closure operator of formal languages with respect to cyclic shifts. We introduce a Gentzen-style calculus and prove cut elimination. Secondly, we…

Logic · Mathematics 2021-11-09 Tikhon Pshenitsyn

Let $B$ be an unilateral weighted backward shift on $\ell_p$, $1 \leq p < \infty$, that admits a $\mathscr{U}$-frequently hypercyclic subspace. We prove that $B$ admits such a subspace free of frequently hypercyclic vectors. The proof…

Functional Analysis · Mathematics 2026-05-11 Nacib G. Albuquerque , Thiago R. Alves , Geraldo Botelho , Vinícius V. Fávaro

An interesting and recently much studied generalization of the classical Schur class is the class of contractive operator-valued multipliers $S$ for the reproducing kernel Hilbert space ${\mathcal H}(k_{d})$ on the unit ball ${\mathbb…

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

Let $X$ be a ball Banach function space on $\mathbb{R}^n$, $k\in\mathbb{N}$, $h\in\mathbb{R}^n$, and $\Delta^k_h$ denote the $k${\rm th} order difference. In this article, under some mild extra assumptions about $X$, the authors prove that,…

Functional Analysis · Mathematics 2025-05-23 Pingxu Hu , Yinqin Li , Dachun Yang , Wen Yuan , Yangyang Zhang

A main objective of the present paper is to develop the theory of hypercyclicity and supercyclicity of linear operators on topological vector space over non-Archimedean valued fields. We show that there does not exist any hypercyclic…

Functional Analysis · Mathematics 2017-08-25 Farrukh Mukhamedov , Otabek Khakimov

Enhancing a recent result of Bayart and Ruzsa we obtain a Birkhoff-type characterization of upper frequently hypercyclic operators and a corresponding Upper Frequent Hypercyclicity Criterion. As an application we characterize upper…

Functional Analysis · Mathematics 2016-01-28 Antonio Bonilla , Karl-G. Grosse-Erdmann

The B_N hyperbolic Sutherland spin model is expressed in terms of a suitable set of commuting Dunkl operators. This fact is exploited to derive a complete family of commuting integrals of motion of the model, thus establishing its…

High Energy Physics - Theory · Physics 2009-11-07 F. Finkel , D. Gomez-Ullate , A. Gonzalez-Lopez , M. A. Rodriguez , R. Zhdanov

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

This paper is devoted to the study of the dynamics of Toeplitz operators $T_F$ with smooth symbols $F$ on the Hardy spaces of the unit disk $H^p$, $p>1$. Building on a model theory for Toeplitz operators on $H^2$ developed by Yakubovich in…

Functional Analysis · Mathematics 2026-01-16 Emmanuel Fricain , Sophie Grivaux , Maëva Ostermann

We construct continuous (and even invertible) linear operators acting on Banach (even Hilbert) spaces whose restrictions to their respective closed linear subspaces of chain recurrent vectors are not chain recurrent operators. This…

Functional Analysis · Mathematics 2025-04-03 Antoni López-Martínez , Dimitris Papathanasiou

We study hypercyclicity of Toeplitz operators in the Hardy space $H^2(\mathbb{D})$ with symbols of the form $R(\overline{z}) +\phi(z)$, where $R$ is a rational function and $\phi \in H^\infty(\mathbb{D})$. We relate this problem to…

Functional Analysis · Mathematics 2021-02-01 Evgeny Abakumov , Anton Baranov , Stéphane Charpentier , Andrei Lishanskii

We extend the de Branges-Beurling theorem characterizing the shift-invariant spaces boundedly contained in the Hardy space of square-summable power series to the full Fock space over $\mathbb{C} ^d$. Here, the full Fock space is identified…

Functional Analysis · Mathematics 2020-07-21 Robert T. W. Martin , Eli Shamovich