Control sets of linear systems on Lie groups

Like in the classical linear Euclidean system, we would like to characterize for a linear control system on a connected Lie group G its control set with nonempty interior that contains the identity of G. We show that many topological properties of this control set are intrinsically connected with the eigenvalues of a derivation associated to the drift of the system. In particular, we prove that if G is a decomposable Lie group there exists only one control set with nonempty interior for the whole linear system. Furthermore, for nilpotent Lie groups we characterize when this set is bounded.