Do internal viscosity models satisfy the fluctuation-dissipation theorem? (Q1205324)

The Brownian forces for a Hookean dumbbell model with internal viscosity are characterized using the fluctuation-dissipation theorem and assuming that the momentum and configuration of the chain fluctuate on separate time scales. A Langevin-type approach in the full phase-space of the dumbbell is used to derive the proper stochastic differential equation. By considering both the stochastic differential equation, or equation of motion, and the equivalent Fokker-Planck equation, or diffusion equation, a contraction is made to the configuration space of the dumbbell. The resulting diffusion equation is compared to the models of previous works employing internal viscosity.