title: Dissipation in monotonic and non-monotonic relaxation to equilibrium.
abstract: Using molecular dynamics simulations, we study field free relaxation from a non-uniform initial density, monitored using both density distributions and the dissipation function. When this density gradient is applied to colour labelled particles, the density distribution decays to a sine curve of fundamental wavelength, which then decays conformally towards a uniform distribution. For conformal relaxation, the dissipation function is found to decay towards equilibrium monotonically, consistent with the predictions of the relaxation theorem. When the system is initiated with a more dramatic density gradient, applied to all particles, non-conformal relaxation is seen in both the dissipation function and the Fourier components of the density distribution. At times, the system appears to be moving away from a uniform density distribution. In both cases, the dissipation function satisfies the modified second law inequality, and the dissipation theorem is demonstrated.
authors.affiliation: Research School of Chemistry, Australian National University, Canberra ACT 0200, Australia.
authors.forename: Charlotte F
authors.initials: CF
authors.lastname: Petersen
authors.affiliation: Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200, Australia.
authors.forename: Denis J
authors.initials: DJ
authors.lastname: Evans
authors.affiliation: Research School of Chemistry, Australian National University, Canberra ACT 0200, Australia.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Williams