In many complex systems, whether biological or artificial, the thermodynamic costs of communication among their components are large. These systems also tend to split information transmitted between any two components across multiple channels. A common hypothesis is that such inverse multiplexing strategies reduce total thermodynamic costs. So far, however, there have been no physics-based results supporting this hypothesis. This gap existed partially because we have lacked a theoretical framework that addresses the interplay of thermodynamics and information in off-equilibrium systems at any spatiotemporal scale. Here we present the first study that rigorously combines such a framework, stochastic thermodynamics, with Shannon information theory. We develop a minimal model that captures the fundamental features common to a wide variety of communication systems. We find that the thermodynamic cost in this model is a convex function of the channel capacity, the canonical measure of the communication capability of a channel. We also find that this function is not always monotonic, in contrast to previous results not derived from first principles physics. These results clarify when and how to split a single communication stream across multiple channels. In particular, we present Pareto fronts that reveal the trade-off between thermodynamic costs and channel capacity when inverse multiplexing. Due to the generality of our model, our findings could help explain empirical observations of how thermodynamic costs of information transmission make inverse multiplexing energetically favorable in many real-world communication systems.

翻译：在许多复杂系统中，无论是生物系统还是人工系统，各组成部分之间的通信都伴随着巨大的热力学成本。这类系统还倾向于将任意两个组件间传输的信息分散到多个通道中。一个常见假设是，这种反向多路复用策略能够降低总热力学成本。然而，迄今为止，尚无基于物理学的理论结果支持这一假设。这一研究空白部分源于我们缺乏一个能够在任意时空尺度上处理非平衡系统中热力学与信息相互作用的理论框架。本文首次将随机热力学这一严谨框架与香农信息论相结合。我们构建了一个能够捕捉各类通信系统共同基本特征的极小模型，发现模型中热力学成本是信道容量（衡量通信能力的标准指标）的凸函数。与以往未基于第一性原理物理推导的结果不同，该函数并非总是单调的。这些结果阐明了何时以及如何将单一通信流拆分为多个通道。特别地，我们给出了帕累托前沿，揭示了反向多路复用时热力学成本与信道容量之间的权衡关系。鉴于模型的普适性，我们的发现可能有助于解释现实世界中许多通信系统因信息传输的热力学成本而使得反向多路复用在能量上更有利的实证观测现象。