We consider the dynamics of fixed size subsystems of an open quantum system, in
which N particles interact via a common quantum noise (reservoir). We show that
correlations among the particles and between the particles and the reservoir, which
are brought about through the interaction for finite N, vanish completely in the high
complexity limit N → ∞. We investigate the effect of the particle system on the
reservoir, which itself is a large quantum system. For each fixed time, we find the
explicit construction of a Hilbert space representation of the asymptotic (N → ∞)
reservoir state and analyze the relation between those representations at different
times
