Classical aspects of quantum fields far from equilibrium.
Classical aspects of quantum fields far from equilibrium.
复制标题
量子场的经典方面远离平衡。
DOI：
10.1103/physrevlett.88.041603
复制
发表时间：
2001
影响因子：
8.6
通讯作者：
J. Berges
中科院分区：
文献类型：
--
作者：
G. Aarts;J. Berges
利用二粒子不可约有效作用量的次首阶1/N展开，研究了O（N）模型中非平衡量子标量场的时间演化。与经典极限下1+1维精确数值模拟的比较表明，对于中等的N值，1/N展开式已经给出了定量的精确结果。对于足够高的初始占有数的量子场的时间演化被证明是准确的经典物理描述。最终，由于经典和量子热平衡之间的差异，对应关系破裂。
We consider the time evolution of nonequilibrium quantum scalar fields in the O(N) model, using the next-to-leading order 1/N expansion of the two-particle irreducible effective action. A comparison with exact numerical simulations in 1+1 dimensions in the classical limit shows that the 1/N expansion gives quantitatively precise results already for moderate values of N. For sufficiently high initial occupation numbers the time evolution of quantum fields is shown to be accurately described by classical physics. Eventually the correspondence breaks down due to the difference between classical and quantum thermal equilibrium.