Universal self-similar dynamics of relativistic and nonrelativistic field theories near nonthermal fixed points
Universal self-similar dynamics of relativistic and nonrelativistic field theories near nonthermal fixed points
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DOI：
10.1103/physrevd.92.025041
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发表时间：
2015-07-27
影响因子：
5
通讯作者：
Berges, Jurgen
中科院分区：
文献类型：
--
作者：
Orioli, Asier Pineiro;Boguslavski, Kirill;Berges, Jurgen
我们研究远离平衡态的孤立多体系统的普遍行为，这与从超冷量子气体到高能粒子物理的广泛应用有关。普遍性是基于非热不动点的存在性，它代表具有自相似标度行为的非平衡吸引子解。相应的动力学普适性类变得非常大，既包括相对论性的，也包括非相对论性的量子和经典系统。对于非相对论（Gross-Pitaevskii）和相对论标量场理论与四次自相互作用的例子，我们证明了红外标度指数以及标度函数一致。我们进行了两个独立的非微扰计算，第一次使用经典统计晶格模拟技术，第二次通过应用顶点图解动力学理论。后者扩展动力学描述的非微扰制度的过度占用模式。我们的研究结果开辟了新的视角，从冷原子实验中了解宇宙早期阶段的动力学。
We investigate universal behavior of isolated many-body systems far from equilibrium, which is relevant for a wide range of applications from ultracold quantum gases to high-energy particle physics. The universality is based on the existence of nonthermal fixed points, which represent nonequilibrium attractor solutions with self-similar scaling behavior. The corresponding dynamic universality classes turn out to be remarkably large, encompassing both relativistic as well as nonrelativistic quantum and classical systems. For the examples of nonrelativistic (Gross-Pitaevskii) and relativistic scalar field theory with quartic self-interactions, we demonstrate that infrared scaling exponents as well as scaling functions agree. We perform two independent nonperturbative calculations, first by using classical-statistical lattice simulation techniques and second by applying a vertex-resummed kinetic theory. The latter extends kinetic descriptions to the nonperturbative regime of overoccupied modes. Our results open new perspectives to learn from experiments with cold atoms aspects about the dynamics during the early stages of our universe.