Active transport in complex environments
Pierre Illien (R. Peierls Centre for Theor. Phys., Oxford University, UK)
Understanding the dynamics of an active or a biased particle in a host medium which hinders its motion is an ubiquitous problem of nonequilibrium statistical physics with important applications, from transport in biological systems to active microrheology. Going beyond the usual effective descriptions of the environment of the active tracer, we propose a model which takes explicitly into account the correlations between the dynamics of the tracer and the response of the bath. Relying on paradigmatic models of statistical mechanics, we determine analytically exact and approximate solutions to this out-of-equilibrium problem. They reveal many striking effects, such as superdiffusion in the high-density limit, velocity anomalies or negative differential mobility.