Tracer and current fluctuations in driven diffusive systems

Interacting particles diffusing in single-file is a fundamental model of transport in narrow channels where particles cannot bypass each other. An important result has been obtained by Kollmann for the mean square displacement of a tracer for any such single-file model. However, since then, no general result has been obtained in the important case where the particles are driven by an external field. Here, we fill this gap and determine the fluctuations and the skewness of the tracer's position for any driven diffusive system. In addition, we also consider a variety of important observables such as the integrated current, the response of the system to the perturbation induced by the displacement of the tracer, and the correlations between several tracers. Furthermore, we also unveil fundamental relations underlying the out-of-equilibrium dynamics of driven diffusive systems. This work constitutes a first step toward a full description of driven one-dimensional systems of interacting particles.
Comment: 6 pages + 20 pages of supplemental material; 3 figures