On the long range correlations of thermodynamic systems out of equilibrium

Understand

Experiments show that macroscopic systems in a stationary nonequilibrium state exhibit long range correlations of the local thermodynamic variables.

• In previous papers we proposed a Hamilton-Jacobi equation for the nonequilibrium free energy as a basic principle of nonequilibrium thermodynamics.
• We show here how an equation for the two point correlations can be derived from the Hamilton-Jacobi equation for arbitrary transport coefficients for dynamics with both external fields and boundary reservoirs.
• In contrast with fluctuating hydrodynamics, this approach can be used to derive equations for correlations of any order.