Run-and-tumble dynamics in a crowded environment: Persistent exclusion process for swimmers

pre_soto_2014

Abstract

The effect of crowding on the run-and-tumble dynamics of swimmers such as bacteria is studied using a discrete lattice model of mutually excluding particles that move with constant velocity along a direction that is randomized at a rate α. In stationary state, the system is found to break into dense clusters in which particles are trapped or stopped from moving. The characteristic size of these clusters predominantly scales as α0.5 in both one and two dimensions. For a range of densities, due to cooperative effects, the stopping time scales as T0.851d and as T0.82d, where Td is the diffusive time associated with the motion of cluster boundaries. Our findings might be helpful in understanding the early stages of biofilm formation.

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