A Zabczyk type method for the study of the exponential trichotomy of discrete dynamical systems

The aim of this paper is to present new discrete-time characterizations for uniform exponential trichotomy of dynamical systems. We obtain necessary and sufficient conditions for the existence of uniform exponential trichotomy of discrete dynamical systems, using a set of computational conditions of Zabczyk type. The main results are applied to deduce new criteria for the detection of the uniform exponential trichotomy of dynamical systems modeled by skew-product flows.