Thermodynamic fluctuation theory for shear flow

A generalization of the Einstein relation for thermodynamic fluctuations is applied to a fluid undergoing Couette flow. It is speculated that if the strain rate fluctuations are to reduce to the known equilibrium results, then the shear dilation effect, that is the variation of the pressure with shear at constant temperature and density, must be a nonanalytic function of strain rate. This conclusion is consistent with computer results obtained previously.