In this paper, we characterize conditions under which a tuple of bounded linear operators is topologically mixing. Also, we give conditions for a tuple to be hereditarily hypercyclic with respect to a tuple of syndeti...In this paper, we characterize conditions under which a tuple of bounded linear operators is topologically mixing. Also, we give conditions for a tuple to be hereditarily hypercyclic with respect to a tuple of syndetic sequences.展开更多
We denote N, R, C the sets of natural, real and complex numbers respectively. Let (λ<sub>n</sub>), n ∈ N be an unbounded sequence of complex numbers. Costakis has proved the following result. There ...We denote N, R, C the sets of natural, real and complex numbers respectively. Let (λ<sub>n</sub>), n ∈ N be an unbounded sequence of complex numbers. Costakis has proved the following result. There exists an entire function f with the following property: for every x, y ∈ R with 0 , every θ ∈(0,1) and every a ∈ C there is a subsequence of natural numbers (m<sub>n</sub>), n ∈ N such that, for every compact subset L ⊆C , In the present paper we show that the constant function a cannot be replaced by any non-constant entire function G. This is so even if one demands the convergence in (*) only for a single radius r and a single positive number θ. This result is related with the problem of existence of common universal vectors for an uncountable family of sequences of translation operators.展开更多
文摘In this paper, we characterize conditions under which a tuple of bounded linear operators is topologically mixing. Also, we give conditions for a tuple to be hereditarily hypercyclic with respect to a tuple of syndetic sequences.
文摘We denote N, R, C the sets of natural, real and complex numbers respectively. Let (λ<sub>n</sub>), n ∈ N be an unbounded sequence of complex numbers. Costakis has proved the following result. There exists an entire function f with the following property: for every x, y ∈ R with 0 , every θ ∈(0,1) and every a ∈ C there is a subsequence of natural numbers (m<sub>n</sub>), n ∈ N such that, for every compact subset L ⊆C , In the present paper we show that the constant function a cannot be replaced by any non-constant entire function G. This is so even if one demands the convergence in (*) only for a single radius r and a single positive number θ. This result is related with the problem of existence of common universal vectors for an uncountable family of sequences of translation operators.
