标题： 随机力在非运动活性物质中增强示踪扩散 显示英文标题

标题： Stochastic Forces Enhance Tracer Diffusion in Non-motile Active Matter

摘要： 随机性是生物系统中成对作用力的一个基本特征，从分子马达到细胞-细胞粘附，然而其对大规模动力学的影响仍不清楚。 在这里，我们表明粒子之间相互但随机波动的相互作用可以产生活性悬浮液，即使在没有自推进或非对称性的情况下，也可以增强外部示踪粒子的扩散。 从一个最小破坏详细平衡的成对动力学晶格模型出发，我们推导出空间-时间密度涨落的粗粒度动力学理论，并揭示了短波长下的有效温度升高。 然后，我们计算了一个与我们的活性流体弱耦合的示踪粒子的自扩散系数，证明纯粹的对称随机相互作用为密集非平衡悬浮液中的增强扩散性提供了一种独特且普遍的途径。 显示英文摘要

摘要： Stochasticity is a defining feature of the pairwise forces governing interactions in biological systems-from molecular motors to cell-cell adhesion-yet its consequences on large-scale dynamics remain poorly understood. Here, we show that reciprocal but randomly fluctuating interactions between particles create active suspensions which can enhance the diffusion of an external tracer particle, even in the absence of self-propulsion or non-reciprocity. Starting from a lattice model with pairwise dynamics that minimally break detailed balance, we derive a coarse-grained dynamical theory for spatio-temporal density fluctuations and reveal an elevated effective temperature at short wavelengths. We then compute the self-diffusion coefficient of a tracer particle weakly coupled to our active fluid, demonstrating that purely reciprocal stochastic interactions provide a distinct and generic route to enhanced diffusivity in dense non-equilibrium suspensions.