Algebraic characterization of autonomy and controllability of behaviours   of spatially invariant systems
  We give algebraic characterizations of the properties of autonomy and of controllability of behaviours of spatially invariant dynamical systems, consisting of distributional solutions, that are periodic in the spatial variables, to a system pf partial differential equations corresponding to a polynomial matrix M in (C[\xi_1,...,\xi_d, \tau])^{m \times n}. 
Amol Sasane
math.OC math.AG math.AP