2025/04/04 by Pei, Ji-Hui, Maes, Christian · 1 citation
#Biological Physics (physics.bio-ph) #FOS: Physical sciences #Soft Condensed Matter (cond-mat.soft) #Statistical Mechanics (cond-mat.stat-mech)
paper · doi:10.48550/arxiv.2504.03210
Can activity be transmitted from smaller to larger scales? We report on such a transfer from a homogeneous active medium to a Newtonian spherical probe. The active medium consists of faster and dilute self-propelled particles, modeled as run-and-tumble particles in 1D or as active Brownian particles in 2D. We derive the reduced fluctuating dynamics of the probe, valid for arbitrary probe velocity, characterized by velocity-dependent friction and noise. In addition to a standard passive regime, we identify peculiar active regimes where the probe becomes self-propelled with high persistence, and its velocity distribution begets peaks at nonzero values. These features are quantitatively confirmed by numerical simulations of the joint probe-medium system. The emergence of active regimes depends not only on the far-from-equilibrium nature of the medium but also on the probe-medium coupling. Our findings reveal how, solely via the induced friction and noise, persistence can cross different scales to transfer active motion.