Département de Physique, École Normale Supérieure, 24 Rue Lhomond, 75 005 Paris, France.
Phys Rev Lett. 2013 Jun 28;110(26):260602. doi: 10.1103/PhysRevLett.110.260602.
The fluctuation theorem characterizes the distribution of the dissipation in nonequilibrium systems and proves that the average dissipation will be positive. For a large system with no external source of fluctuation, fluctuations in properties will become unobservable and details of the fluctuation theorem are unable to be explored. In this Letter, we consider such a situation and show how a fluctuation theorem can be obtained for a small open subsystem within the large system. We find that a correction term has to be added to the large system fluctuation theorem due to correlation of the subsystem with the surroundings. Its analytic expression can be derived provided some general assumptions are fulfilled, and its relevance is checked using numerical simulations.
涨落定理刻画了非平衡系统中耗散的分布，并证明平均耗散将为正。对于没有外部涨落源的大系统，涨落将变得不可观测，因此无法探索涨落定理的细节。在这封信中，我们考虑了这种情况，并展示了如何从小系统的角度来研究大系统中的涨落定理。我们发现，由于子系统与环境的相关性，需要在大系统的涨落定理中添加一个修正项。只要满足一些一般假设，就可以推导出它的解析表达式，并通过数值模拟来检验它的相关性。
