Abstract: The LQ-optimal state feedback of a finite-dimensional linear time-invariant system determines a coprime factorization NM-1 of the transfer function. We show that the same is true also for infinite-dimensional systems over arbitrary Hilbert spaces, in the sense that the factorization is weakly coprime, i.e., Nf, Mf H2 = f H2 for every function f. The factorization need not be B
Kalle M. Mikkola