Work fluctuation relations for a dragged Brownian particle in active bath

Abstract

We study the work distribution of a Brownian particle diffusing in an environment of active particles and being trapped in a harmonic potential, the center of which is subjected to a time-dependent protocol. Employing phase space path integral technique we find an expression of work distribution for any generic model of active noise. Here we consider two active noise models — Gaussian correlated and Poisson white, each of which can represent some physical systems. For both the cases, it is found that transient fluctuation relation of work is not applicable though at steady state it holds by defining a renormalized temperature τr in place of bath temperature. Interestingly, τr is the same for both the models and can be expressed in terms of diffusivities of active and thermal noises. For correlated Gaussian bath, an alternative approach is presented. Analogous to the formalism given by Hatano and Sasa (2001), we obtain a work like quantity from nonequilibrium potential with the inclusion of a new stationary parameter Ω. With proper choice of Ω, a steady-state fluctuation relation, namely Jarzynski equality is satisfied.