On the Boundedness of a Recurrence Sequence in a Banach Space

Abstract

We investigate the problem of the boundedness of the following recurrence sequence in a Banach space B: $x_n = \sum\limits_{k = 1}^\infty {A_k x_{n - k} + y_n } ,{ }n \geqslant 1,{ }x_n = {\alpha}_n ,{ }n \leqslant 0,$ where |y _n} and |α _n } are sequences bounded in B, and A _k, k ≥ 1, are linear bounded operators. We prove that if, for any ε > 0, the condition $\sum\limits_{k = 1}^\infty {k^{1 + {\varepsilon}} \left\| {A_k } \right\| < \infty }$ is satisfied, then the sequence |x _n} is bounded for arbitrary bounded sequences |y _n} and |α _n } if and only if the operator $I - \sum {_{k = 1}^\infty {\text{ }}z^k A_k }$ has the continuous inverse for every z ∈ C, | z | ≤ 1.