Group Actions as Stroboscopic Maps of Ordinary Differential Equations
  Discrete-time dynamical systems can be derived from group actions. In the present work possibility of application of this method to systems of ordinary differential equations is studied. Invertible group actions are considered as possible candidates for stroboscopic maps of ordinary differential equations. It is shown that flow of the Bloch equation is a unique suspension of an invertible map on the SU(2) group. 
A. Okninski