Ballistic macroscopic fluctuation theory
Ballistic macroscopic fluctuation theory
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DOI：
10.21468/scipostphys.15.4.136
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发表时间：
2022-06
期刊：
影响因子：
5.5
通讯作者：
B. Doyon;G. Perfetto;T. Sasamoto;T. Yoshimura
中科院分区：
文献类型：
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作者：
B. Doyon;G. Perfetto;T. Sasamoto;T. Yoshimura
我们介绍了一个新的通用框架，描述量子和经典多体系统的波动和相关性，在欧拉流体动力学尺度的空间和时间。该框架适应传统的宏观波动理论（MFT）的想法，支持弹道传输的系统。由此产生的“弹道MFT”（BMFT）是完全基于多体系统的欧拉流体动力学数据。在这个框架内，介观观测量是经典的随机变量，只依赖于波动的保守密度，欧拉尺度波动通过确定性传输热力学波动通过欧拉流体力学。使用BMFT，我们表明，在空间中的长程相关一般随着时间的推移，从长波长的非均匀的初始状态在相互作用的模型。这一结果，我们通过数值计算验证，挑战了长期以来的范式，在欧拉尺度，流体细胞可以被认为是不相关的。我们还表明，Gallavotti-Cohen波动定理的非平衡弹道输运纯粹从时间反演不变性的欧拉流体力学。我们检查BMFT的有效性，通过将其应用到可积系统，特别是硬棒气体，与广泛的模拟，证实我们的分析结果。
We introduce a new universal framework describing fluctuations and correlations in quantum and classical many-body systems, at the Euler hydrodynamic scale of space and time. The framework adapts the ideas of the conventional macroscopic fluctuation theory (MFT) to systems that support ballistic transport. The resulting “ballistic MFT” (BMFT) is solely based on the Euler hydrodynamics data of the many-body system. Within this framework, mesoscopic observables are classical random variables depending only on the fluctuating conserved densities, and Euler-scale fluctuations are obtained by deterministically transporting thermodynamic fluctuations via the Euler hydrodynamics. Using the BMFT, we show that long-range correlations in space generically develop over time from long-wavelength inhomogeneous initial states in interacting models. This result, which we verify by numerical calculations, challenges the long-held paradigm that at the Euler scale, fluid cells may be considered uncorrelated. We also show that the Gallavotti-Cohen fluctuation theorem for non-equilibrium ballistic transport follows purely from time-reversal invariance of the Euler hydrodynamics. We check the validity of the BMFT by applying it to integrable systems, and in particular the hard-rod gas, with extensive simulations that confirm our analytical results.