10 citations · 18 across the 10 of their papers we have counts for
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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,...…
Common hypercyclic vectors for certain families of differential operators
Nikos Tsirivas
Let (k(n)) n=1,2,... be a strictly increasing sequence of positive integers . We consider a specific sequence of differential operators Tk(n),λ , n=1,2,... on the space of entire f…
Common hypercyclic vectors for families of backward shift operators
Nikos Tsirivas
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 stro…
Universal Taylor series on specific compact sets
Nikos Tsirivas
Let be the open unit disc in the complex plane. We denote by the set of complex numbers and consider any compact set which is disjoint from and which also…
A general lower bound for the asymptotic convergence factor
Nikos Tsirivas
We provide a rather general and very simple to compute lower bound for the asymptotic convergence factor of compact subsets of the set of complex numbers with connected complement…