Zero orders and dimensions of some invariant subspaces in linear structured systems (Q1411655)

The paper deals with structured linear systems, represented by means of directed graphs, and its invariants under a large group of transformations including state feedback. The authors focus on a number of fundamental invariants and develop graph-theoretic characterizations for the generic versions of these invariants. They obtain a complete characterization of the zero structure of a structured linear system. The authors also give a graph-theoretic characterization of the generic dimensions of the maximal output-nulling invariant and controllability subspaces.