Entropy production in classical Yang-Mills theory from Glasma initial conditions
Entropy production in classical Yang-Mills theory from Glasma initial conditions
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Glasma 初始条件下经典杨-米尔斯理论中的熵产生
DOI：
10.1103/physrevd.88.094006
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
A. Schaefer and T.T. Takahashi
中科院分区：
文献类型：
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作者：
H.Iida;T. Kunihiro;B. Mueller;A. Ohnishi;A. Schaefer and T.T. Takahashi
本文从噪声类玻璃初始条件出发，研究了经典Yang-Mills场论中的热化过程。Kunihiroet al.将熵产生与Kolmogorov-Sinaï熵联系起来，该熵给出了经典混沌系统中的熵产生率，从纯随机初始场配置开始，对经典Yang-Mills场进行了数值计算。相反，我们在这里研究类似玻璃的初始条件。对于小的随机波动，我们得到了质量上相似的结果，而当这种波动不存在时，没有观察到熵的增加。我们分析了几个时间窗的中间时间Lyapunov谱，并计算了Kolmogorov-Sinaï熵。我们发现在时间演化的早期阶段有大量的正李亚普诺夫指数。此外，对于以后的时间，它们的数量是自由度总数的相当大的一部分。正李雅普诺夫指数谱起初变化迅速，后来趋于稳定，表明规范场的动力学接近稳定状态。因此，我们得出结论，对于类似玻璃的初始条件，经典胶子场动力学产生了大量的熵。
We study the thermalization process in classical Yang–Mills field theory starting from noisy glasmalike initial conditions by investigating the initial-value sensitivity of trajectories. Kunihiroet al.linked entropy generation to the Kolmogorov–Sinaï entropy, which gives the entropy production rate in classical chaotic systems, calculated numerically for classical Yang–Mills fields starting from purely random initial field configurations. In contrast, we study here glasmalike initial conditions. For small random fluctuations, we obtain qualitatively similar results, while no entropy increase is observed when such fluctuations are absent. We analyze the intermediate-time Lyapunov spectrum for several time windows and calculate the Kolmogorov–Sinaï entropy. We find a large number of positive Lyapunov exponents at the early stages of time evolution. Also, for later times, their number is a sizeable fraction of the total number of degrees of freedom. The spectrum of positive Lyapunov exponents at first changes rapidly but then stabilizes, indicating that the dynamics of the gauge fields approaches a steady state. Thus, we conclude that also for glasmalike initial conditions, a significant amount of entropy is produced by classical gluon field dynamics.