Inflation after false vacuum decay: Observational prospects after Planck
Inflation after false vacuum decay: Observational prospects after Planck
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DOI：
10.1103/physrevd.91.083527
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发表时间：
2013-09
影响因子：
5
通讯作者：
R. Bousso;D. Harlow;L. Senatore
中科院分区：
文献类型：
--
作者：
R. Bousso;D. Harlow;L. Senatore
我们通过虚假真空的衰变来评估宇宙形成的两个潜在信号。负空间曲率是一种可能性，但其检测窗口现在很小。然而，另一个可能的信号是大角度宇宙微波背景（CMB）功率谱的抑制。这是由于有效势的陡峭造成的，因为它插入了平坦的通货膨胀平台和将我们与母体真空分开的高屏障之间。我们证明这两种效应可以在角度尺度上参数分离。从观察来看，陡峭效应似乎在很大程度上被排除在外 $\ensuremath{\ell}$;但它与 WMAP 和普朗克合作发现的低于 $\ensuremath{\ell}\ensuremath{\approx}30$ 的功率略有不足保持一致。我们给出了两个简单的模型，可以提高普朗克数据的拟合度；一种具有可观察到的曲率，一种没有。尽管存在宇宙差异，我们认为未来的宇宙微波背景极化和最重要的大规模结构观测应该能够证实普朗克异常（如果它是真实的）。如果我们进一步假设亚稳态真空景观的具体理论设置，如弦理论所建议的那样，我们可以估计在宇宙微波背景中看到低$\ensuremath{\ell}$抑制的概率。这种计算存在很大的理论不确定性，但我们认为可检测到的抑制的概率可能高达 $O(1)$，并且通常明显大于看到曲率的概率。
We assess two potential signals of the formation of our universe by the decay of a false vacuum. Negative spatial curvature is one possibility, but the window for its detection is now small. However, another possible signal is a suppression of the cosmic microwave background (CMB) power spectrum at large angles. This arises from the steepening of the effective potential as it interpolates between a flat inflationary plateau and the high barrier separating us from our parent vacuum. We demonstrate that these two effects can be parametrically separated in angular scale. Observationally, the steepening effect appears to be excluded at large $\ensuremath{\ell}$; but it remains consistent with the slight lack of power below $\ensuremath{\ell}\ensuremath{\approx}30$ found by the WMAP and Planck collaborations. We give two simple models which improve the fit to the Planck data; one with observable curvature and one without. Despite cosmic variance, we argue that future CMB polarization and most importantly large-scale structure observations should be able to corroborate the Planck anomaly if it is real. If we further assume the specific theoretical setting of a landscape of metastable vacua, as suggested by string theory, we can estimate the probability of seeing a low-$\ensuremath{\ell}$ suppression in the CMB. There are significant theoretical uncertainties in such calculations, but we argue the probability for a detectable suppression may be as large as $O(1)$, and in general is significantly larger than the probability of seeing curvature.