Classical Information Exchange Between Particles

Abstract: The flow of information within many-body systems is a fundamental feature of physical interaction. Given an underlying classical physics model for the interaction between a particle and its environment, we give meaning to and quantify the information passed between them over time. We show that the maximum information exchange rate is proportional to the ratio of inter-particle energy flow and initial particle energy -- a sort of signal-to-noise ratio. In addition, a single time-point (as opposed to trajectory) observability relation emerges.