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Related papers: Common hypercyclic vectors and universal functions

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We treat the question of existence of common hypercyclic vectors for families of continuous linear operators. It is shown that for any continuous linear operator $T$ on a complex Fr\'echet space $X$ and a set $\Lambda\subseteq \R_+\times\C$…

Functional Analysis · Mathematics 2012-09-07 Stanislav Shkarin

We provide a sufficient condition for an operator $T$ on a non-metrizable and sequentially separable topological vector space $X$ to be sequentially hypercyclic. This condition is applied to some particular examples, namely, a composition…

Functional Analysis · Mathematics 2024-03-08 Alfred Peris

Motivated by a question posed by Sophie Grivaux concerning the regularity of the orbits of frequently hypercylic operators, we show the following: for any operator $T$ on a separable metrizable and complete topological vector space $X$…

Functional Analysis · Mathematics 2019-06-25 Yunied Puig

We provide necessary and sufficient conditions on the existence of common hypercyclic vectors for multiples of the backward shift operator along sparse powers. Our main result strongly generalizes corresponding results which concern the…

Functional Analysis · Mathematics 2015-06-15 Nikos Tsirivas

We provide criteria for the existence of upper frequently hypercyclic subspaces and for common hypercyclic subspaces, which include the following consequences. There exist frequently hypercyclic operators with upper-frequently hypercyclic…

Dynamical Systems · Mathematics 2015-12-22 Juan Bès , Quentin Menet

A tuple $(T_1,\dots,T_n)$ of continuous linear operators on a topological vector space $X$ is called hypercyclic if there is $x\in X$ such that the the orbit of $x$ under the action of the semigroup generated by $T_1,\dots,T_n$ is dense in…

Dynamical Systems · Mathematics 2010-08-23 Stanislav Shkarin

Given a dynamical system $(X,T)$ and a family $\mathsf{I}\subseteq \mathcal{P}(\omega)$ of "small" sets of nonnegative integers, a point $x \in X$ is said to be $\mathsf{I}$-strong universal if for each $y \in X$ there exists a subsequence…

Functional Analysis · Mathematics 2025-05-12 Paolo Leonetti

We study density properties of orbits for a hypercyclic operator $T$ on a separable Banach space $X$, and show that exactly one of the following four cases holds: (1) every vector in $X$ is asymptotic to zero with density one; (2) generic…

Functional Analysis · Mathematics 2026-01-29 Jian Li , Xinsheng Wang , Jianjie Zhao

Bonet, Frerick, Peris and Wengenroth constructed a hypercyclic operator on the locally convex direct sum of countably many copies of the Banach space $\ell_1$. We extend this result. In particular, we show that there is a hypercyclic…

Functional Analysis · Mathematics 2014-02-26 Stanislav Shkarin

A bounded linear operator $T$ on a Banach space $X$ is called hypercyclic if there exists a vector $x \in X$ such that $orb{(x,T)}$ is dense in $X$. The Hypercyclicity Criterion is a well-known sufficient condition for an operator to be…

Functional Analysis · Mathematics 2020-02-06 André Augusto , Leonardo Pellegrini

Let $X$ be a complex topological vector space with dim$(X)>1$ and $\mathcal{B}(X)$ the space of all continuous linear operators on $X$. In this paper, we extend the concept of supercyclicity of a single operators and strongly continuous…

Functional Analysis · Mathematics 2018-10-18 Mohamed Amouch , Otmane Benchiheb

We study the spaceability of the set of recurrent vectors $\text{Rec}(T)$ for an operator $T:X\longrightarrow X$ on a Banach space $X$. In particular: we find sufficient conditions for a quasi-rigid operator to have a recurrent subspace;…

Functional Analysis · Mathematics 2024-06-11 Antoni López-Martínez

Let T be a bounded linear operator acting on a complex Banach space X and (\lambda_n) a sequence of complex numbers. Our main result is that if |\lambda_n|/|\lambda_{n+1}| \to 1 and the sequence (\lambda_n T^n) is frequently universal then…

Functional Analysis · Mathematics 2013-10-14 George Costakis , Ioannis Parissis

A linear operator $U$ acting boundedly on an infinite-dimensional separable complex Hilbert space $H$ is universal if every linear bounded operator acting on $H$ is similar to a scalar multiple of a restriction of $U$ to one of its…

Functional Analysis · Mathematics 2024-06-05 Luciano Abadías , F. Javier González-Doña , Jesús Oliva-Maza

It is proved that, if $(P_n)$ is a sequence of polynomials with complex coefficients having unbounded valences and tending to infinity at sufficiently many points, then there is an infinite dimensional closed subspace of entire functions,…

Complex Variables · Mathematics 2025-01-17 L. Bernal-González , M. C. Calderón-Moreno , J. López-Salazar , J. A. Prado-Bassas

We study the existence of a common hypercyclic vector for different families of composition operators.

Functional Analysis · Mathematics 2007-05-23 Frederic Bayart

A criterion to obtain frequent hypercyclicity for a sequence of convolution operators on the space of entire functions on the complex plane is provided. The criterion involves that the generating functions of the operators do not vanish on…

Complex Variables · Mathematics 2026-02-24 L. Bernal-González , M. C. Calderón-Moreno , J. A. Prado-Bassas

The sets of strongly supercyclic, weakly l-sequentially supercyclic, weakly sequentially supercyclic, and weakly supercyclic vectors for an arbitrary normed-space operator are all dense in the normed space, regardless the notion of…

Functional Analysis · Mathematics 2021-02-03 C. S. Kubrusly

A bounded operator on a real or complex separable infinite-dimensional Banach space $Z$ is universal in the sense of Glasner and Weiss if for every invertible ergodic measure-preserving transformation $T$ of a standard Lebesgue probability…

Dynamical Systems · Mathematics 2015-12-18 Sophie Grivaux

We completely characterize the finite dimensional subsets A of any separable Hilbert space for which the notion of A-hypercyclicity coincides with the notion of hypercyclicity, where an operator T on a topological vector space X is said to…

Functional Analysis · Mathematics 2018-08-17 S. Charpentier , R. Ernst