Universal infrared scaling of gravitational wave background spectra
Universal infrared scaling of gravitational wave background spectra
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DOI：
10.1103/physrevd.102.083528
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发表时间：
2019-09
影响因子：
5
通讯作者：
R. Cai;Shi Pi;M. Sasaki
中科院分区：
文献类型：
--
作者：
R. Cai;Shi Pi;M. Sasaki
研究了在一定动力学自由度下，由双线性形式的应力张量产生的随机引力波背景功率谱的一般红外行为。我们发现$\Omega_{\text{GW}}\propto k^3$的一个非常广泛的一类源，满足一组合理的条件。也就是说，当源项在频率和时间上都有界时，$k^3$标度是普遍有效的，在辐射占主导地位的阶段是有效的，并且对于$k$小于与源相关的所有物理标度，如峰值频率，峰值宽度和持续时间等。我们还讨论了可能违反这些条件及其物理影响。
We study the general infrared behavior of the power spectrum of a stochastic gravitational wave background produced by stress tensor in the form bilinear in certain dynamical degrees of freedom. We find $\Omega_{\text{GW}}\propto k^3$ for a very wide class of the sources which satisfy a set of reasonable conditions. Namely, the $k^3$ scaling is universally valid when the source term is bounded in both frequency and time, is effective in a radiation-dominated stage, and for $k$ smaller than all the physical scales associated with the source, like the peak frequency, peak width, and time duration, etc.. We also discuss possible violations of these conditions and their physical implications.