论文标题
宇宙学相变的速度以及对重力波的影响
Speed of sound in cosmological phase transitions and effect on gravitational waves
论文作者
论文摘要
宇宙学一阶相变的重力波的能量预算取决于气泡壁周围两个阶段热等离子体中的声速。在实时的增强标准模型中工作，该模型接受了强大的两步电动相变，我们将高阶校正计算为压力和声速。我们将结果与低阶近似值与声速和能量预算进行比较，并研究对重力波信号的影响。我们发现，在我们的高阶计算中，声音速度偏离$ C_S^2 = 1/3 $的偏差最多可提高到$ \ MATHCAL O（5 \％）$。与假设$ c_s^2 = 1/3 $相比，这会导致能源预算的抑制作用高达$ \ MATHCAL O（50 \％）$。该作用对于混合和爆炸溶液最为重要。我们将讨论概括为多个惰性标量和减少费米昂家族的情况，以模仿假设的黑暗扇区相变。在具有修改场含量的该扇区中，声速可以得到明显的抑制作用，并具有潜在的魔力顺序对重力波幅度的影响。
The energy budget for gravitational waves of a cosmological first order phase transitions depends on the speed of sound in the thermal plasma in both phases around the bubble wall. Working in the real-singlet augmented Standard Model, which admits a strong two-step electroweak phase transition, we compute higher order corrections to the pressure and sound speed. We compare our result to lower-order approximations to the sound speed and the energy budget and investigate the impact on the gravitational wave signal. We find that deviations in the speed of sound from $c_s^2 = 1/3$ are enhanced up to $\mathcal O(5\%)$ in our higher-order computation. This results in a suppression in the energy budget of up to $\mathcal O (50\%)$ compared to approximations assuming $c_s^2 = 1/3$. The effect is most significant for hybrid and detonation solutions. We generalise our discussion to the case of multiple inert scalars and the case of a reduced number of fermion families in order to mimic hypothetical dark sector phase transitions. In this sector with modified field content, the sound speed can receive significant suppression, with potential order-of-magnitude impact on the gravitational wave amplitude.
