“…Stabilization of linear autonomous control systems is classically done in finite dimension by poleshifting or by Riccati theory (see, e.g., [25,29,40,43]). In infinite dimension, pole-shifting may be used for some appropriate classes of systems (see [5,10,11], see also [37, page 711] and [48,Chapter 3]), but such approaches rely on spectral considerations and in practice require the numerical computation of eigenelements, which may be hard in general. Riccati theory has also been much explored in infinite dimension (see, e.g., [12,26,27,49] and provides a powerful way for stabilizing a linear control system.…”