Quantum macrostatistical picture of nonequilibrium steady states

We employ a quantum macrostatistical treatment of irreversible processes to prove that, in nonequilibrium steady states, (a) the hydrodynamical observables execute a generalised Onsager-Machlup process and (b) the spatial correlations of these observables are generically of long range. The key assumptions behind these results are a nonequilibrium version of Onsager's regression hypothesis, together with certain hypotheses of chaoticity and local equilibrium for hydrodynamical fluctuations.