论文标题

从与普朗克弹跳宇宙学的束缚中限制双光谱

Constraining the bispectrum from bouncing cosmologies with Planck

论文作者

van Tent, Bartjan, Delgado, Paola C. M., Durrer, Ruth

论文摘要

弹跳宇宙学模型,例如在循环量子宇宙学中,可以是通货膨胀阶段,并在宇宙微波背景(CMB)中观察到的近距离不变的波动光谱。但是,它们通常不是高斯,也会产生双光谱。这些模型可以通过考虑在非常大的尺度上考虑实质性的非豪斯率来帮助减轻CMB的大规模异常,从而在亚匹配尺度上呈指数衰减。因此,人们认为这种非高斯性在观察结果中不会可见,这只能探测亚想要的尺度。在这封信中,我们表明具有参数的弹跳模型可以大大减轻CMB的大规模异常,而Planck数据具有很高的意义,具体取决于特定模型,$ 5.4 $,$ 6.4 $或$ 14 $ 14 $。

Bouncing models of cosmology, as they arise e.g. in loop quantum cosmology, can be followed by an inflationary phase and generate close-to-scale-invariant fluctuation spectra as observed in the Cosmic Microwave Background (CMB). However, they are typically not Gaussian and also generate a bispectrum. These models can help to mitigate the large-scale anomalies of the CMB by considering substantial non-Gaussianities on very large scales, which decay exponentially on sub-horizon scales. It was therefore thought that this non-Gaussianity would not be visible in observations, which can only probe sub-horizon scales. In this letter we show that bouncing models with parameters such that they can significantly mitigate the large-scale anomalies of the CMB are excluded by the Planck data with high significance of, depending on the specific model, $5.4$, $6.4$ or $14$ standard deviations.

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