We investigate the production of axion quanta during the early universe evolution of an axion-like field rolling down a wiggly potential. We compute the growth of quantum fluctuations and their back-reaction on the homogeneous zero-mode. We evaluate the transfer of kinetic energy from the zero mode to the quantum fluctuations and the conditions to decelerate the axion zero-mode as a function of the Hubble rate, the slope of the potential, the size of the barriers and the initial field velocity. We discuss how these effects impact the relaxion mechanism.

中文翻译：

---

轴子碎片

我们研究了轴子状场沿摆动势滚动的早期宇宙演化过程中轴子量子的产生。我们计算了量子涨落的增长及其对均匀零模式的反作用。我们评估动能从零模式到量子涨落的转移，以及轴子零模式减速的条件，作为哈勃速率、电位斜率、势垒大小和初始场速的函数。我们讨论这些影响如何影响松弛机制。