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arXiv 1811.09151astro-ph.COgr-qchep-phhep-th
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原初非高斯性在引力波谱上的印记

Imprints of Primordial Non-Gaussianity on Gravitational Wave Spectrum

Caner Unal

摘要:

虽然宇宙微波背景和大尺度结构对宇宙最大尺度的探测精度越来越高,但除了原始黑洞的边界外,我们对更小尺度的认识仍然非常有限。我们证明了小尺度量子涨落的统计性质可以通过随机引力波背景来探测,该背景是由标量模重新进入视界引起的。我们发现,即使标量曲率波动有一个次主导的非高斯分量,这些非高斯扰动源的主要部分的诱导GWS。此外,由非高斯标量波动产生的GW在更高的频率处达到峰值,这可以导致独特的观测特征。我们发现,灵敏的下一代干涉仪,这将/可能达到$Ω_{GW}h^2 \sim 10^{-15}$(如PTA-SKA,LISA,DECIGO,BBO,CE,ET),可以探测$f_{NL} \sim 0.5$这是甚至比预测的下一代CMB实验。如果检测到感应的GW背景,但没有检测到由非高斯分量$ζ= ζ_G + f_{\rm NL} \, ζ_G^{2}$产生的签名,则这转化为取决于GW信号的幅度和宽度的对$f_{\rm NL}$的界限。如果根本没有检测到诱导的GW背景,则这转化为标量波动的界限。结果与PBH是DM还是电流能量密度的完全可忽略部分无关。

英文摘要:

Although Cosmic Microwave Background and Large Scale Structure probe the largest scales of our universe with ever increasing precision, our knowledge about the smaller scales is still very limited other than the bounds on Primordial Black Holes. We show that the statistical properties of the small scale quantum fluctuations can be probed via the stochastic gravitational wave background, which is induced as the scalar modes re-enter the horizon. We found that even if scalar curvature fluctuations have a subdominant non-Gaussian component, these non-Gaussian perturbations can source a dominant portion of the induced GWs. Moreover, the GWs sourced by non-Gaussian scalar fluctuations peaks at a higher frequency and this can result in distinctive observational signatures. We found that the sensitive next-generation-interferometers, which will/could reach $Ω_{GW}h^2 \sim 10^{-15}$ (such as PTA-SKA, LISA, DECIGO, BBO, CE, ET), can probe $f_{NL} \sim 0.5$ which is even better than the predictions of the next generation CMB experiments. If the induced GW background is detected, but not the signatures arising from the non-Gaussian component, $ζ= ζ_G + f_{\rm NL} \, ζ_G^{2}$, this translates into bounds on $f_{\rm NL}$ depending on the amplitude and the width of the GW signal. If the induced GW background is not detected at all, this translates into bounds on scalar fluctuations. The results are independent from the fact that whether PBH are DM or completely negligible part of the current energy density.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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