论文标题
广义流体动力学时间的演变是由象征扩展产生的
How generalized hydrodynamics time evolution arises from a form factor expansion
论文作者
论文摘要
普遍的流体动力学（GHD）形式主义已成为研究（1+1）二维整合模型中空间不均匀量子淬灭的宝贵工具。 GHD的主要范式是，在后期，可以将本地可观察物作为具有时空依赖化学势的广义吉布斯集合平均值计算。但是，目前尚不清楚这种半古老的GHD图片是如何从完整的量子动力学中出现的。我们基于淬灭作用方法评估了在空间不均匀淬灭中局部可观察物的量子时间演变，在这种方法中，可以根据有限透射状态周围的形式扩展来表达可观察物。我们展示了GHD形式主义是如何作为形式膨胀的主要项而出现的，涉及有限透射状态顶部的一个粒子孔对。从这张图片来看，如何将量子校正计算为GHD是完全透明的，这是由于外形因素扩展中的较高项所产生的。我们的计算基于相对论现场理论的结果，尽管我们的论点可能可以推广到通用的可集成模型。
The generalized hydrodynamics (GHD) formalism has become an invaluable tool for the study of spatially inhomogeneous quantum quenches in (1+1)-dimensional integrable models. The main paradigm of the GHD is that at late times local observables can be computed as generalized Gibbs ensemble averages with space-time dependent chemical potentials. It is, however, still unclear how this semiclassical GHD picture emerges out of the full quantum dynamics. We evaluate the quantum time evolution of local observables in spatially inhomogeneous quenches, based on the quench action method, where observables can be expressed in terms of a form factor expansion around a finite-entropy state. We show how the GHD formalism arises as the leading term in the form factor expansion, involving one particle-hole pair on top of the finite-entropy state. From this picture it is completely transparent how to compute quantum corrections to GHD, which arise from the higher terms in the form factor expansion. Our calculations are based on relativistic field theory results, though our arguments are likely generalizable to generic integrable models.
