66 citations · 92 across the 10 of their papers we have counts for
13 papers
Multiplicative structures of hypercyclic functions for convolution operators
Luis Bernal-González, J. Alberto Conejero, George Costakis +1
In this note, it is proved the existence of an infinitely generated multiplicative group consisting of entire functions that are, except for the constant function 1, hypercyclic wi…
Common hypercyclic vectors and universal functions
George Costakis, Nikos Tsirivas
Let X,Y be two separable Banach or Frechet spaces , and (Tn) , n=1,2,... be a sequence from linear and continuous operators from X to Y . We say that the sequence (Tn) , n=1,2,...…
Non-existence of common hypercyclic entire functions for certain families of translation operators
George Costakis, Nikos Tsirivas, Vagia Vlachou
We show that families of translation operators, where the translates grow exponentially fast, do not admit common hypercyclic functions. The result is close to be optimal.
Dynamics of perturbations of the identity operator by multiples of the backward shift on
George Costakis, Antonios Manoussos, Amir Bahman Nasseri
Let , be the unweighted backward shift and the identity operator respectively on , the space of bounded sequences over the complex numbers endowed wi…
Recurrent Linear Operators
George Costakis, Antonios Manoussos, Ioannis Parissis
We study the notion of recurrence and some of its variations for linear operators acting on Banach spaces. We characterize recurrence for several classes of linear operators such a…
Szemeredi's theorem, frequent hypercyclicity and multiple recurrence
George Costakis, Ioannis Parissis
Let T be a bounded linear operator acting on a complex Banach space X and (λ_n) a sequence of complex numbers. Our main result is that if |λ_n|/|λ_{n+1}| \to 1 and the sequence (λ_…