title: Stochastic thermodynamics of fluctuating density fields: non-equilibrium free energy differences under coarse-graining.
abstract: We discuss the stochastic thermodynamics of systems that are described by a time-dependent density field, for example, simple liquids and colloidal suspensions. For a time-dependent change of external parameters, we show that the Jarzynski relation connecting work with the change of free energy holds if the time evolution of the density follows the Kawasaki-Dean equation. Specifically, we study the work distributions for the compression and expansion of a two-dimensional colloidal model suspension implementing a practical coarse-graining scheme of the microscopic particle positions. We demonstrate that even if coarse-grained dynamics and density functional do not match, the fluctuation relations for the work still hold albeit for a different, apparent, change of free energy.
authors.affiliation: II. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Leonard
authors.forename: B
authors.initials: B
authors.lastname: Lander
authors.forename: U
authors.initials: U
authors.lastname: Seifert
authors.forename: T
authors.initials: T
authors.lastname: Speck