title: Probing local equilibrium in nonequilibrium fluids.
abstract: We use extensive computer simulations to probe local thermodynamic equilibrium (LTE) in a quintessential model fluid, the two-dimensional hard-disks system. We show that macroscopic LTE is a property much stronger than previously anticipated, even in the presence of important finite-size effects, revealing a remarkable bulk-boundary decoupling phenomenon in fluids out of equilibrium. This allows us to measure the fluid's equation of state in simulations far from equilibrium, with an excellent accuracy comparable to the best equilibrium simulations. Subtle corrections to LTE are found in the fluctuations of the total energy which strongly point to the nonlocality of the nonequilibrium potential governing the fluid's macroscopic behavior out of equilibrium.
authors.affiliation: Institute Carlos I for Theoretical and Computational Physics, and Departamento de Electromagnetismo y Física de la Materia, Universidad de Granada, 18071 Granada, Spain.
authors.forename: J J
authors.initials: JJ
authors.lastname: del Pozo
authors.affiliation: Institute Carlos I for Theoretical and Computational Physics, and Departamento de Electromagnetismo y Física de la Materia, Universidad de Granada, 18071 Granada, Spain.
authors.forename: P L
authors.initials: PL
authors.lastname: Garrido
authors.affiliation: Institute Carlos I for Theoretical and Computational Physics, and Departamento de Electromagnetismo y Física de la Materia, Universidad de Granada, 18071 Granada, Spain.
authors.forename: P I
authors.initials: PI
authors.lastname: Hurtado