关于不稳定激励的流体力学
On the Hydrodynamics of Unstable Excitations
摘要：
广义流体动力学（GHD）方法在描述各种可积多体量子系统的非平衡性质方面非常成功。它自然地提取了系统的大尺度动力学自由度，因此是对涌现现象的特别好的探测。一个这样的现象是不稳定粒子的存在，传统上通过散射矩阵的特殊分析结构来观察。由于其有限的寿命和能量阈值，这些特别难以研究。本文将GHD方法应用于同时具有不稳定激发和量子可积性的模型。已知具有这些特征的相对论性可积量子场论的最大家族是齐次正弦-戈登模型。我们认为最简单的非平凡的例子，这样的理论和调查的效果不稳定的激发各种物理量，无论是在平衡和非平衡态所产生的分区协议。流体动力学方法揭示了不稳定粒子的物理学，通过散射矩阵的分析结构远远超出了它的定义，并澄清了它对理论的平衡和非平衡性质的影响。至关重要的是，在这个动力学的角度来看，我们确定不稳定的粒子作为有限寿命的束缚态的共同传播的稳定粒子的不同类型，并观察如何稳定的人口不稳定粒子出现在高温热浴。
英文摘要：
The generalized hydrodynamic (GHD) approach has been extremely successful in describing the out-of-equilibrium properties of a great variety of integrable many-body quantum systems. It naturally extracts the large-scale dynamical degrees of freedom of the system, and is thus a particularly good probe for emergent phenomena. One such phenomenon is the presence of unstable particles, traditionally seen via special analytic structures of the scattering matrix. Because of their finite lifetime and energy threshold, these are especially hard to study. In this paper we apply the GHD approach to a model possessing both unstable excitations and quantum integrability. The largest family of relativistic integrable quantum field theories known to have these features are the homogeneous sine-Gordon models. We consider the simplest non-trivial example of such theories and investigate the effect of an unstable excitation on various physical quantities, both at equilibrium and in the non-equilibrium state arising from the partitioning protocol. The hydrodynamic approach sheds new light onto the physics of the unstable particle, going much beyond its definition via the analytic structure of the scattering matrix, and clarifies its effects both on the equilibrium and out-of-equilibrium properties of the theory. Crucially, within this dynamical perspective, we identify unstable particles as finitely-lived bound states of co-propagating stable particles of different types, and observe how stable populations of unstable particles emerge in large-temperature thermal baths.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
