Semianalytic calculation of gravitational wave spectrum nonlinearly induced from primordial curvature perturbations
Semianalytic calculation of gravitational wave spectrum nonlinearly induced from primordial curvature perturbations
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DOI：
10.1103/physrevd.97.123532
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发表时间：
2018-04
影响因子：
5
通讯作者：
K. Kohri;T. Terada
中科院分区：
文献类型：
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作者：
K. Kohri;T. Terada
无论暴胀过程中产生的原始引力波（GW）是否足够强到可以观测到，GW都必然是由二阶扰动的原始曲率扰动产生的。诱导的GWs可以通过在小尺度上增强的曲率扰动或宇宙学历史中物质主导阶段的存在而增强。我们解析地计算了诱导GWs的功率谱表达式中的积分，这是一个与原始曲率摄动谱无关的通用部分。这使得后续的数值积分非常容易。在简单的情况下，我们导出了诱导GW谱的完全解析公式。
Whether or not the primordial gravitational wave (GW) produced during inflation is sufficiently strong to be observable, GWs are necessarily produced from the primordial curvature perturbations in the second order of perturbation. The induced GWs can be enhanced by curvature perturbations enhanced at small scales or by the presence of matter-dominated stages of the cosmological history. We analytically calculate the integral in the expression of the power spectrum of the induced GWs which is a universal part independent of the spectrum of the primordial curvature perturbations. This makes the subsequent numerical integrals significantly easy. In simple cases, we derive fully analytic formulas for the induced GW spectrum.