Nano-Hz Gravitational-Wave Signature from Axion Dark Matter
Nano-Hz Gravitational-Wave Signature from Axion Dark Matter
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Axion 暗物质的纳赫兹引力波特征
DOI：
10.1103/physrevlett.126.121301
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发表时间：
2021
影响因子：
8.6
通讯作者：
Urakawa Yuko
中科院分区：
文献类型：
--
作者：
Kitajima Naoya;Soda Jiro;Urakawa Yuko
我们计算了由轴子暗物质产生的U（1）规范场的随机引力波背景的精确谱。规范场的爆炸性产生很快使线性分析的适用性失效，需要非线性格式。我们利用数值晶格模拟来正确地遵循非线性动力学，如反反应和再散射，这对引力波的发射做出了重要贡献。事实证明，具有衰变常数和给出正确暗物质丰度的质量的轴子预测了SKA可检测到的圆偏振引力波信号。我们还表明，由此产生的引力波谱有可能解释NANOGrav 12.5年的数据。
We calculate the accurate spectrum of the stochastic gravitational-wave background from U(1) gauge fields produced by axion dark matter. The explosive production of gauge fields soon invalidates the applicability of the linear analysis and one needs nonlinear schemes. We make use of numerical lattice simulations to properly follow the nonlinear dynamics such as backreaction and rescattering which gives important contributions to the emission of gravitational waves. It turns out that the axion with the decay constantand the masswhich gives the correct dark matter abundance predicts the circularly polarized gravitational-wave signature detectable by SKA. We also show that the resulting gravitational-wave spectrum has a potential to explain NANOGrav 12.5 yr data.