Continuous and discrete dynamical sampling

In this paper we study the continuous dynamical sampling problem at infinite time in a complex Hilbert space H. We find necessary and sufficient conditions on bounded linear operator A∈B(H) set of vectors G⊂H, order to obtain that {etAg}g∈G,t∈[0,∞) is semi-continuous frame for if it possible discretize variable t still have also relate iteration etA G discrete (A′)n G′ an adequate A′ G′⊂H.