Numerical simulations of gravitational waves from early-universe turbulence
Numerical simulations of gravitational waves from early-universe turbulence
复制标题
早期宇宙湍流引力波的数值模拟
DOI：
10.1103/physrevd.102.083512
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
A. Kosowsky
中科院分区：
文献类型：
--
作者：
Alberto Roper Pol;Sayan Mandal;A. Brandenburg;T. Kahniashvili;A. Kosowsky
我们进行直接的数值模拟的磁流体动力学湍流在早期宇宙和数值计算所产生的随机背景的引力波和遗迹磁场。这些模拟并不像早期的分析工作那样做简单的假设。如果假设湍流在产生时的能量携带尺度约为哈勃半径的百分之一，正如在一阶相变中所预期的那样，引力波功率的峰值将在电弱尺度产生的信号的mHz频率范围内。引力波（GW）产生的效率随着湍流的驱动方式而显着变化。计划中的激光干涉仪空间天线（丽莎）在电弱尺度上对湍流的探测能力需要在等离子体运动或磁场中有0.1%至10%的热等离子体能量密度，这取决于驱动过程的模型。我们的研究结果预测了一个新的普遍形式低于谱峰频率，比以前认为的更浅。这意味着在低频范围内GW能谱的较大值。这将用丽莎检测湍流的范围扩展到较低的频率，对应于比假设的能量携带尺度更高的能量尺度。
We perform direct numerical simulations of magnetohydrodynamic turbulence in the early universe and numerically compute the resulting stochastic background of gravitational waves and relic magnetic fields. These simulations do not make the simplifying assumptions of earlier analytic work. If the turbulence is assumed to have an energy-carrying scale that is about a hundredth of the Hubble radius at the time of generation, as expected in a first-order phase transition, the peak of gravitational wave power will be in the mHz frequency range for a signal produced at the electroweak scale. The efficiency of gravitational wave (GW) production varies significantly with how the turbulence is driven. Detectability of turbulence at the electroweak scale by the planned Laser Interferometer Space Antenna (LISA) requires anywhere from 0.1% to 10% of the thermal plasma energy density to be in plasma motions or magnetic fields, depending on the model of the driving process. Our results predict a new universal form below the spectral peak frequency that is shallower than previously thought. This implies larger values of the GW energy spectra in the low-frequency range. This extends the range where turbulence is detectable with LISA to lower frequencies, corresponding to higher energy scales than the assumed energy-carrying scale.
DOI：
10.1088/1475-7516/2020/03/024
发表时间：
2020-03-01
影响因子：
6.4
作者：
Caprini, Chiara;Chala, Mikael;Weir, David J.
通讯作者：
Weir, David J.