论文标题

通过高阶热力学不确定性关系提高跑步粒子系统的熵产生速率的估计

Improving estimation of entropy production rate for run-and-tumble particle systems by high-order thermodynamic uncertainty relation

论文作者

Bao, Ruicheng, Hou, Zhonghuai

论文摘要

熵产生在活动物质系统的调节和稳定性中起着重要作用,其速率量化了这些系统的非平衡性质。但是,即使在某些简单的活性系统(例如分子电动机或细菌)中,也很难估算熵的产生,该系统可以通过跑步粒子(RTP)建模,后者是主动事项研究中的代表性模型。在这里,我们解决了一个不对称的RTP在一维中的问题,首先为RTP构建有限的热力学不确定性关系(TUR),在短期观察时间方面效果很好,用于熵产生估计。然而,当活动主导时,RTP远非平衡,从TUR转弯到熵产生的下限是微不足道的。我们通过引入最近提出的高阶热力学不确定性关系(HTUR)来解决这个问题,其中电流的累积生成函数用作关键成分。为了利用HTUR,我们采用了一种新颖的方法来分析我们研究的当前的累积生成函数,而无需明确了解时间依赖性的概率分布。事实证明,HTUR能够准确估计稳态耗散率,因为累积的生成函数涵盖了电流的高阶统计,包括除了其方差外,罕见和大波动。与常规TUR相比,HTUR可以显着改善能量耗散的估计,即使在遥远的平衡状态下也可以很好地工作。我们还基于改进的结合提供了一种策略,以估算适度轨迹数据的熵产生,以实现可行性。

Entropy production plays an important role in the regulation and stability of active matter systems, and its rate quantifies the nonequilibrium nature of these systems. However, entropy production is hard to be experimentally estimated even in some simple active systems like molecular motors or bacteria, which may be modeled by the run-and-tumble particle (RTP), a representative model in the study of active matters. Here we resolve this problem for an asymmetric RTP in one-dimension, firstly constructing a finite time thermodynamic uncertainty relation (TUR) for a RTP, which works well in the short observation time regime for entropy production estimation. Nevertheless, when the activity dominates,i.e., the RTP is far from equilibrium, the lower bound for entropy production from TUR turns to be trivial. We address this issue by introducing a recently proposed high-order thermodynamic uncertainty relation (HTUR), in which the cumulant generating function of current serve as a key ingredient. To exploit the HTUR, we adopt a novel method to analytically obtain the cumulant generating function of the current we study, with no need to explicitly know the time-dependent probability distribution. The HTUR is demonstrated to be able to estimate the steady state energy dissipation rate accurately because the cumulant generating function covers higher-order statistics of the current, including rare and large fluctuations besides its variance. Compared to the conventional TUR, the HTUR could give significantly improved estimation of energy dissipation, which can work well even in the far-from equilibrium regime. We also provide a strategy based on the improved bound to estimate the entropy production from moderate amount of trajectory data for experimental feasibility.

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