The role of information flow in active matter

信息流在活性物质中的作用

• 批准号: 498288081
• 负责人: Dr. Sarah Loos
• 金额: --
• 依托单位: Department of Applied Mathematics and Theoretical Physics (DAMTP)
• 依托单位国家: 德国
• 项目类别: WBP Fellowship
• 财政年份: 2022
• 资助国家: 德国
• 起止时间: 2021-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/498288081?language=en
• 关键词: role; information; flow; active; matter

Living and artificial active systems, such as bacteria, robots, birds, or pedestrians, display intriguing dynamics from individual to collective systems, where self-organised states like swarms and flocks occur. Due to the ongoing conversion of energy from a ‘fuel’ source (e.g. ATP) into persistent motion, such systems naturally operate far from thermal equilibrium and their theoretical description therefore poses major challenges. Recently, there is considerable interest in describing active systems by means of stochastic thermodynamics, specifically, in measuring time-reversal symmetry breaking of individual trajectories by the fluctuating entropy production. Important open problems are to link the entropy production to the underlying heat dissipation and ‘thermodynamic cost’ of the ‘activity’, and to link this measure of irreversibility on different levels of coarse-graining. For example, recent research aims to formulate a thermodynamics on the level of stochastic hydrodynamic field equations. However, in addition to the energy-conversion, there are further crucial differences between active and passive systems, such as the abilities to perceive, communicate, remember, and react. Despite the obvious relevance of these features for the individual and collective dynamics, the study of information exchange in active matter is still in its infancy. In this proposal, we aim to put forward our general understanding of the role of information flow for active matter. The second central goal is to connect the information flow to thermodynamic principles. Our idea is to use the theory of information-thermodynamics previously established for systems subject to feedback control. Indeed, it is well-known that only by taking into account information-theoretic quantities, the total entropy production and the heat dissipation of systems subject to feedback can be linked with each other, namely in the form of generalised second laws. Here we aim to analogously derive generalised second laws for active matter, containing the continuous information flow between environment and active particle, or between individual particles in a collective. To increase the generality of our investigations, we consider a single active swimmer, a particle-based system of many interacting swimmers, and a hydrodynamic field model of a collective active system. Using these models, we want to investigate what kind of information flows occur, what direction they have, and we want to demonstrate that this quantity is an important piece of the puzzle of a consistent thermodynamic description. Specifically, we aim to investigate the relation between ‘swarming’, ‘pattern formation’, local entropy production and the arising local information flows.

生物和人工活动系统，如细菌、机器人、鸟类或行人，展示了从个体到集体系统的有趣动态，其中出现了自组织状态，如蜂群和羊群。由于能量从“燃料”源（如ATP）持续转化为持续运动，这种系统自然地远离热平衡，因此它们的理论描述提出了重大挑战。近年来，人们对用随机热力学来描述有源系统，特别是用波动熵产生来测量单个轨迹的时间反转对称性破缺，产生了相当大的兴趣。重要的开放问题是将熵的产生与潜在的散热和“活动”的“热力学成本”联系起来，并将这种不可逆性的测量与不同层次的粗粒度联系起来。例如，最近的研究旨在在随机水动力场方程的水平上建立热力学。然而，除了能量转换之外，主动系统和被动系统之间还有进一步的关键差异，例如感知、交流、记忆和反应的能力。尽管这些特征与个体和集体动力学有明显的相关性，但对活性物质中信息交换的研究仍处于起步阶段。在这个提议中，我们的目标是提出我们对信息流对活性物质的作用的一般理解。第二个中心目标是将信息流与热力学原理联系起来。我们的想法是利用先前建立的信息热力学理论，用于受反馈控制的系统。事实上，众所周知，只有考虑到信息论的量，总熵的产生和受反馈影响的系统的散热才能相互联系，即以广义第二定律的形式联系起来。在这里，我们的目标是类似地推导出活性物质的广义第二定律，包含环境和活性粒子之间或集体中单个粒子之间的连续信息流。为了增加我们研究的通用性，我们考虑了一个单一的主动游泳者，一个由许多相互作用的游泳者组成的基于粒子的系统，以及一个集体主动系统的水动力场模型。利用这些模型，我们想要研究信息流的类型，它们的方向，我们想要证明这个量是一致的热力学描述的重要组成部分。具体来说，我们的目标是研究“蜂群”、“模式形成”、局部熵产生和产生的局部信息流之间的关系。