论文标题
CMB中的大规模异常和弹跳宇宙学的非高斯语异常
Large scale anomalies in the CMB and non-Gaussianity in bouncing cosmologies
论文作者
论文摘要
我们建议，在CMB的大尺度上观察到的几个异常在通货膨胀时代之前发生的宇宙反弹中具有共同的起源。反弹在问题中引入了一个新的物理规模，这打破了通货膨胀的几乎规模的不变性。结果，通货膨胀开始时标量扰动的状态不再是束式真空吸尘器，而是包含激发和非高斯性，对于红外模式而言更大。我们认为，这些激发的综合作用以及CMB模式与更长的波长扰动之间的相关性可以解释观察到的功率抑制，对于偶性不对称，并且还可以偏爱奇数 - 偏见相关性。该模型还可以减轻镜头幅度$ a_l $中的张力。我们通过用一些自由参数来表征模型，而不是限于特定的弹跳理论来采用现象学观点。我们确定了我们的想法所需的最低成分集，并指出了满足这些条件的文献中理论的例子。
We propose that several of the anomalies that have been observed at large angular scales in the CMB have a common origin in a cosmic bounce that took place before the inflationary era. The bounce introduces a new physical scale in the problem, which breaks the almost scale invariance of inflation. As a result, the state of scalar perturbations at the onset of inflation is no longer the Bunch-Davies vacuum, but it rather contains excitations and non-Gaussianity, which are larger for infrared modes. We argue that the combined effect of these excitations and the correlations between CMB modes and longer wavelength perturbations, can account for the observed power suppression, for the dipolar asymmetry, and it can also produce a preference for odd-parity correlations. The model can also alleviate the tension in the lensing amplitude $A_L$. We adopt a phenomenological viewpoint by characterizing the model with a few free parameters, rather than restricting to specific bouncing theories. We identify the minimum set of ingredients needed for our ideas to hold, and point out examples of theories in the literature where these conditions are met.
