标题： 自推进粒子在基底上的非高斯行为 显示英文标题

标题： Non-Gaussian behaviour of a self-propelled particle on a substrate

摘要： 由投影内部力驱动的自推进粒子的过阻尼布朗运动通过解析求解朗之万方程进行研究。 正在研究的“主动”粒子被限制在一条线性通道内移动。 其内部力的方向在一个垂直于基底的平面内的单位圆上进行取向扩散。 一个额外的时间依赖力矩作用在内部力方向上。 该模型适用于如催化驱动的Janus粒子和在基底上移动的细菌等主动粒子。 给出了前四个时间依赖位移矩的解析结果，并对几种特殊情况进行了分析。 当力矩消失时，在有限时间t时，粒子位移的归一化峰度不为零，表明存在显著的动力学非高斯行为，随着长时间趋于零，并具有1/t的长时尾部。 显示英文摘要

摘要： The overdamped Brownian motion of a self-propelled particle which is driven by a projected internal force is studied by solving the Langevin equation analytically. The "active" particle under study is restricted to move along a linear channel. The direction of its internal force is orientationally diffusing on a unit circle in a plane perpendicular to the substrate. An additional time-dependent torque is acting on the internal force orientation. The model is relevant for active particles like catalytically driven Janus particles and bacteria moving on a substrate. Analytical results for the first four time-dependent displacement moments are presented and analysed for several special situations. For vanishing torque, there is a significant dynamical non-Gaussian behaviour at finite times t as signalled by a non-vanishing normalized kurtosis in the particle displacement which approaches zero for long time with a 1/t long-time tail.