“…While this topic of fundamental interest has a long tradition in physics and mathematics, conventionally explored via master equations [6,9], dynamical semi-groups [3,6] and algebraic scattering theory [16,33], many recent works focus on a quantum resonance theory approach. The latter has been applied successfully to systems close to equilibrium [18,[27][28][29] and far from equilibrium [19,26]. In both situations, one of the main questions is the (time-) asymptotic behaviour of a quantum system consisting of a subsystem S interacting with one or several other subsystems, given by thermal reservoirs R 1 , .…”