论文标题
在Ligo的第二个观察过程中搜索由原始曲率扰动引起的随机重力波背景
Search for the stochastic gravitational-wave background induced by primordial curvature perturbations in LIGO's second observing run
论文作者
论文摘要
由于非线性模式耦合，预计以早期宇宙的辐射为主时代的原始密度扰动有望产生随机重力波（GWS）。在此\ emph {letter}中，我们在第二次观察运行期间（O2）报告了两个Ligo检测器数据中的随机GW背景的搜索。我们专注于com的vavenumbers $ 10^{16} -10^{18}〜{\ rm mpc}^{ - 1} $的原始扰动。我们没有在数据中找到这种随机信号的任何结论性证据，因此在这些尺度下对功率谱的幅度放置了第一个基于GW的约束。我们假定对原始扰动的功率谱和高斯统计数据的对数正态形状，并改变功率谱的宽度以覆盖狭窄和宽光谱。功率谱幅度的派生上限（$ 95 \％$）为$ 0.01-0.1 $。作为副产品，我们能够在超级原始黑洞中推断上宇宙质量的上限（$ m_ \ mathrm {pbh} \ simeq 10^{ - 20} -20} -10^{ - 19} m _ {\ odot} $ $ 10^} $ 10^}。
Primordial density perturbations in the radiation-dominated era of the early Universe are expected to generate stochastic gravitational waves (GWs) due to nonlinear mode coupling. In this \emph{Letter}, we report on a search for such a stochastic GW background in the data of the two LIGO detectors during their second observing run (O2). We focus on the primordial perturbations in the range of comoving wavenumbers $10^{16}-10^{18}~{\rm Mpc}^{-1}$ for which the stochastic background falls within the detectors' sensitivity band. We do not find any conclusive evidence of this stochastic signal in the data, and thus place the very first GW-based constraints on the amplitude of the power spectrum at these scales. We assume a lognormal shape for the power spectrum and Gaussian statistics for the primordial perturbations, and vary the width of the power spectrum to cover both narrow and broad spectra. Derived upper limits ($95\%$) on the amplitude of the power spectrum are $0.01-0.1$. As a byproduct, we are able to infer upper limits on the fraction of the Universe's mass in ultralight primordial black holes ($M_\mathrm{PBH} \simeq 10^{-20}-10^{-19}M_{\odot}$) at their formation time to be $\lesssim 10^{-25}$.
