论文标题
从真空和轴突状膨胀期间产生的引力波背景
Gravitational wave background from vacuum and thermal fluctuations during axion-like inflation
论文作者
论文摘要
鉴于通气量与非亚伯利亚拓扑电荷密度的耦合可能导致快速热量热浴的产生，我们将重新审视类似轴突的通货膨胀的框架。包括色散（质量）和吸收性（摩擦）效应。对于现象学上可行的参数，该系统仍处于较弱的通货膨胀状态（热摩擦$ \ ll $ hubble速率）。对于张量扰动，我们得出了一个插值公式，该公式同时融合了真空和热产生。后者在Lisa窗口中产生与模型无关的频率形状$ \ sim F_0^3 $，其系数允许测量热时期的最大剪切粘度。但是，要找到系数足够大以至于可以观察到的模型是一个挑战。
We revisit the framework of axion-like inflation in view of the possibility that the coupling of the inflaton to a non-Abelian topological charge density could lead to the generation of a rapidly thermalizing heat bath. Both dispersive (mass) and absorptive (friction) effects are included. For phenomenologically viable parameters, the system remains in a weak regime of warm inflation (thermal friction $\ll$ Hubble rate). For tensor perturbations we derive an interpolating formula that incorporates both vacuum and thermal production. The latter yields a model-independent frequency shape $\sim f_0^3$ in the LISA window, whose coefficient allows to measure the maximal shear viscosity of the thermal epoch. It is a challenge, however, to find models where the coefficient is large enough to be observable.
