Active Ornstein-Uhlenbeck particle under stochastic resetting

Abstract

We investigate the dynamics of an inertial active Ornstein-Uhlenbeck (OU) particle in the presence of stochastic resetting. Using renewal approach, we compute the mean square displacement (MSD) and position probability distribution functions both in the overdamped and underdamped regimes. In contrast to the normal active OU particle, the MSD of an active OU particle with resetting displays an initial diffusive and long-time or steady-state non-diffusive behavior. The steady-state MSD gets suppressed with an increase in the resetting rate and approaches zero for an infinitely large resetting rate. Moreover, it has a nonmonotonic impact on the duration of activity. For an intermediate range of activity time, the steady-state MSD is enhanced, allowing the particle to explore a larger region, thereby increasing the probability of encountering a wide-spread target. Moreover, when the particle is suspended in a viscoelastic medium characterized by the presence of finite memory, the MSD interestingly develops an intermediate-time plateau and the plateau depends on the strength of the viscoelasticity and the viscoelastic relaxation time. With an increase in strength of the viscoelasticity, the width of the plateau increases and the MSD suppresses. In addition, slow viscoelastic relaxation makes memory effects weaker and hence the intermediate plateau disappears and steady state MSD gets enhanced, implying low strength and longer persistence of memory are beneficial for a wide spread target search. Similarly, for slow resetting, the intermediate plateau is more distinct, whereas fast resetting results in the system approaching steady state faster, overcoming the intermediate plateau in MSD. This emerging behavior might be due to the complex interplay between the resetting mechanism, activity, and memory effects. Finally, our analytical results are in good agreement with numerical simulation.