论文标题
胶体粒子的动力学耦合到高斯磁场：从依赖限制到非线性记忆
Dynamics of a colloidal particle coupled to a Gaussian field: from a confinement-dependent to a non-linear memory
论文作者
论文摘要
浸入复杂培养基中的胶体粒子的有效动力学通常是用过度阻尼的线性Langevin方程来描述的，其速度与记忆核的速度，该记忆核决定有效的（时间依赖性）摩擦和波动的相关性。最近，在实验和数值模拟中已经显示，该内存可能取决于粒子所进行的可能的光学限制，这表明该描述即使在平衡处也不会忠实地捕获胶体的实际动力学。在这里，我们提出了一种不同的方法，其中我们将介质建模为与胶体线性耦合的高斯场。胶体粒子的产生有效演化方程具有非线性记忆项，该记忆项扩展了先前的模型，并在存在下的实验和数值证据上解释了。这个非线性术语与我们得出的新型波动散动有关，与有效噪声的相关性有关。
The effective dynamics of a colloidal particle immersed in a complex medium is often described in terms of an overdamped linear Langevin equation for its velocity with a memory kernel which determines the effective (time-dependent) friction and the correlations of fluctuations. Recently, it has been shown in experiments and numerical simulations that this memory may depend on the possible optical confinement the particle is subject to, suggesting that this description does not capture faithfully the actual dynamics of the colloid, even at equilibrium. Here, we propose a different approach in which we model the medium as a Gaussian field linearly coupled to the colloid. The resulting effective evolution equation of the colloidal particle features a non-linear memory term which extends previous models and which explains qualitatively the experimental and numerical evidence in the presence of confinement. This non-linear term is related to the correlations of the effective noise via a novel fluctuation-dissipation relation which we derive.
