(334c) Statistical Effects Associated with Tracking Propulsive Particles

The propulsion of active particles leads to dynamics and fluctuations that are different from passive Brownian fluctuations at equilibrium. These effects are easier to quantify in the limit of strong propulsion in which the particles move in nearly-straight lines for long times. As active particles become used in a wider array of applications, it has become important to understand the dynamics and fluctuations in situations in which propulsion is comparable in magnitude to thermal fluctuations. We have used computer simulations to quantify the fluctuations of active particles in this region of parameters. In addition to depending on the speed of the particles, the character of the fluctuations depends strongly on the timescale over which they are quantified. We have also determined the implications of these fluctuations for tracking propulsive particles to extract their properties. Because of the distribution of motions that occur, simple fitting procedures can lead to a bias in the extracted properties.