“…An important motivation for our work comes from the theory of persistently excited control systems, in which one considers systems of the form (1.3)ẋ(t) = Ax(t) + α(t)Bu(t), with x(t) ∈ R d , u(t) ∈ R m , A and B matrices with real entries and appropriate dimensions, and α a (T, µ)-persistently exciting (PE) signal for some positive constants T ≥ µ, i.e., a signal α ∈ L ∞ (R + , [0, 1]) satisfying, for every t ≥ 0, (1.4) t+T t α(s) ds ≥ µ (cf. Chaillet, Chitour, Loría, and Sigalotti [5], Chitour, Colonius, and Sigalotti [9], Chitour, Mazanti, and Sigalotti [10], Chitour and Sigalotti [11], Srikant and Akella [33]). Notice that, when α takes its values in {0, 1}, (1.3) can be seen as a particular case of (1.1) by adding a trivial subsystem (cf.…”