Tracer dynamics in an interacting active bath: fluctuations and energy partition
arXiv:2504.15250 · doi:10.1088/1367-2630/adfd06
Abstract
We investigate the dynamics of a massive tracer particle coupled to an interacting active bath, modeled as a harmonic chain of overdamped active particles analytically, with an aim to understand the impact of bath interactions and activity on the nonequilibrium fluctuations of the tracer. From the microscopic equations, we derive the tracer particle's effective Langevin equation, obtaining the dissipative and stochastic forces from the bath. We analyze the friction kernel, revealing power-law tails in the weak coupling limit and exponential decay in the strong coupling regime. Due to the interplay between bath interactions, probe-bath coupling, and activity, the mean squared displacement, velocity, and stationary velocity correlations exhibit different dynamical regimes, which we characterize analytically. Under harmonic confinement, we find that energy equipartition holds at low activity but breaks down at higher activity, with the kinetic energy exhibiting a non-monotonic dependence on the activity of the bath.
27 pages, 10 figures
References in corpus (48)
- Active Particles in Complex and Crowded Environments
- Active Brownian Particles. From Individual to Collective Stochastic Dynamics
- How far from equilibrium is active matter?
- Statistical Mechanics of Active Ornstein Uhlenbeck Particles
- Self-Starting Micromotors in a Bacterial Bath
- The statistical physics of active matter: from self-catalytic colloids to living cells
- Steady state, relaxation and first-passage properties of a run-and-tumble particle in one-dimension
- Generalized energy equipartition in harmonic oscillators driven by active baths
- Nonequilibrium equation of state in suspensions of active colloids
- Transport powered by bacterial turbulence
- Foundation of Fractional Langevin Equation: Harmonization of a Many Body Problem
- Active Brownian Motion in Two Dimensions
- The nonequilibrium glassy dynamics of self-propelled particles
- Run-and-tumble particles in two-dimensions : Marginal position distributions
- Energy dissipation and violation of the fluctuation-response relation in non-equilibrium Langevin systems
- Anomalous Polymer Dynamics Is Non-Markovian: Memory Effects and The Generalized Langevin Equation Formulation
- The Anomalous Transport of Tracers in Active Baths
- Generalized Langevin Equation Formulation for Anomalous Polymer Dynamics
- Tracer diffusion in active suspensions
- Fluctuating motion in an active environment
- Modeling the dynamics of a tracer particle in an elastic active gel
- Active Brownian Motion with Directional Reversals
- Non-equilibrium fluctuations and nonlinear response of an active bath
- On the Einstein relation between mobility and diffusion coefficient in an active bath
- Tracer dynamics in one dimensional gases of active or passive particles
- On the generalized Langevin equation for a Rouse bead in a nonequilibrium bath
- From Langevin to generalized Langevin equations for the nonequilibrium Rouse model
- Effective Langevin equations for a polar tracer in an active bath
- Activity driven transport in harmonic chains
- A Brownian cyclic engine operating in a viscoelastic active suspension
- Passive particle in an active bath: How can we tell it is out of equilibrium?
- Non-Gaussian anomalous dynamics in systems of interacting run-and-tumble particles
- Stationary states of activity-driven harmonic chains
- Brownian particle in a Poisson-shot-noise active bath: exact statistics, effective temperature, and inference
- Stochastic thermodynamics of a probe in a fluctuating correlated field
- Quantum Brownian Motion: Drude and Ohmic Baths as Continuum Limits of the Rubin Model
- Dynamical fluctuations of a tracer coupled to active and passive particles
- The fluctuation-dissipation relation holds for a macroscopic tracer in an active bath
- Force renormalization for probes immersed in an active bath
- Second Law of Thermodynamics without Einstein Relation
- Pair Dispersion in Dilute Suspension of Active Swimmers
- Dynamical crossovers and correlations in a harmonic chain of active particles
- Spatial correlations of hydrodynamic fluctuations in simple fluids under shear flow: A mesoscale simulation study
- When does an active bath behave as an equilibrium one?
- Harmonically trapped inertial run-and-tumble particle in one dimension
- Tagged particle behavior in a harmonic chain of direction reversing active Brownian particles
- Violation of the second fluctuation-dissipation relation and entropy production in nonequilibrium medium
- Harmonic chain driven by active Rubin bath: transport properties and steady-state correlations