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arXiv 0907.1453astro-ph.CO
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探测CMB中的遗迹引力波:普朗克实验与地基实验的比较

Detecting Relic Gravitational Waves in the CMB: Comparison of Planck and Ground-based Experiments

W. Zhao, W. Zhang

摘要:

比较了两种即将开展的宇宙微波背景辐射(CMB)实验,即空间普朗克卫星和各种地面实验对残余引力波的探测能力。与地面实验相比,普朗克卫星可以观测到所有多极区的CMB功率谱,但仪器噪声要大得多。我们发现,对于张量标量比$Δr$的不确定性,北极熊(II)作为一个典型的地面实验可以给出比普朗克卫星小得多的值。然而,对于光谱指数$Δn_t$的不确定性,普朗克可以给出与北极熊(II)相似的结果。如果结合这两个实验,则$Δn_t$的值可以减小2倍。对于含$r=0.1$的模型,可望达到约束$Δn_t=0.10$,这为研究极早期宇宙的物理提供了一个极好的机会。我们还发现,在最大尺度($\ell<20$)的观察是非常重要的约束的光谱指数$n_t$。因此,有必要结合未来空间和地基CMB实验的观测结果来确定遗留的引力波。

英文摘要:

We compare the detection abilities for the relic gravitational waves by two kinds of forthcoming cosmic microwave background radiation (CMB) experiments, space-based Planck satellite and the various ground-based experiments. Comparing with the ground-based experiments, Planck satellite can observe all the CMB power spectra in all the multipole range, but having much larger instrumental noises. We find that, for the uncertainty of the tensor-to-scalar ratio $Δr$, PolarBear (II) as a typical ground-based experiment can give much smaller value than Planck satellite. However, for the uncertainty of the spectral index $Δn_t$, Planck can give the similar result with PolarBear (II). If combining these two experiments, the value of $Δn_t$ can be reduced by a factor 2. For the model with $r=0.1$, the constraint $Δn_t=0.10$ is expected to be achieved, which provides an excellent opportunity to study the physics in the very early universe. We also find the observation in the largest scale ($\ell<20$) is very important for constraining the spectral index $n_t$. So it is necessary to combine the observations of the future space-based and ground-based CMB experiments to determine the relic gravitational waves.

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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