Holography for inflation using conformal perturbation theory
Holography for inflation using conformal perturbation theory
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DOI：
10.1007/jhep04(2013)047
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发表时间：
2012-11
影响因子：
5.4
通讯作者：
A. Bzowski;Paul McFadden;Kostas Skenderis
中科院分区：
文献类型：
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作者：
A. Bzowski;Paul McFadden;Kostas Skenderis
本文给出了一类暴胀慢滚模型的精确的、定量的全息描述。双QFT是一个变形的三维CFT由一个几乎边际运营商，其中，在我们考虑的模型中，产生RG流到附近的IR固定点。这些模型描述了山顶暴胀，其中暴胀子从无限过去（对应于双QFT的IR固定点）的局部最大值滚动到无限未来（对应于双QFT的UV）的附近局部最小值。通过纯全息方法，我们计算了标量和张量宇宙学微扰的谱和双谱。这些可观测量全息映射到的QFT双折射可以使用共形微扰理论计算，即使当对偶QFT是强耦合的。光谱和双谱都可以用CFT变换器来表达，CFT变换器通过共形不变性固定，直到几个常数。因此，慢卷暴胀微扰子的形式是由德西特等距从不动点的微扰破缺决定的。将常数设置为AdS/CFT在固定点处获得的值，我们发现与已知的慢滚功率谱和非高斯性表达式完全一致。
We provide a precise and quantitative holographic description of a class of inflationary slow-roll models. The dual QFT is a deformation of a three-dimensional CFT by a nearly marginal operator, which, in the models we consider, generates an RG flow to a nearby IR fixed point. These models describe hilltop inflation, where the inflaton rolls from a local maximum of the potential in the infinite past (corresponding to the IR fixed point of the dual QFT) to reach a nearby local minimum in the infinite future (corresponding to the UV of the dual QFT). Through purely holographic means, we compute the spectra and bispectra of scalar and tensor cosmological perturbations. The QFT correlators to which these observables map holographically may be calculated using conformal perturbation theory, even when the dual QFT is strongly coupled. Both the spectra and the bispectra may be expressed this way in terms of CFT correlators that are fixed, up to a few constants, by conformal invariance. The form of slow-roll inflationary correlators is thus determined by the perturbative breaking of the de Sitter isometries away from the fixed point. Setting the constants to their values obtained by AdS/CFT at the fixed point, we find exact agreement with known expressions for the slow-roll power spectra and non-Gaussianities.