论文标题
广义非本地$ r^2 $的通货膨胀中的非高斯通货膨胀
Non-Gaussianities in generalized non-local $R^2$-like inflation
论文作者
论文摘要
In [1], a most general higher curvature non-local gravity action was derived that admits a particular $R^2$-like inflationary solution predicting the spectral index of primordial scalar perturbations $n_s(N)\approx 1-\frac{2}{N}$, where $N$ is the number of e-folds before the end of inflation, $N\gg 1$, any value of the张量表与量表$ r（n）<0.036 $，张量tilt $ n_t（n）$违反$ r = -8n_t $条件。 In this paper, we compute scalar primordial non-Gaussianities (PNGs) in this theory and effectively demonstrate that higher curvature non-local terms lead to reduced bispectrum $f_{\rm NL}\left( k_1,\,k_2,\,k_3 \right)$ mimicking several classes of scalar field models of inflation known in the literature.我们获得了$ \ vert f _ {\ rm nl} \ vert \ sim o（1-10）$（1-10）$在等边，正交和挤压限制以及由数量$ \ vert $ \ vert \ frac {d \ ln f _ {d \ ln f _ {d d d d d ln v _ { k} \ vert \ sillsim 1 $。这样的PNG足够大，可以通过未来的CMB和大规模结构观测值来测量，从而提供了探测量子重力性质的可能性。此外，我们证明了重力的非本地修改中的$ r^2 $类似通货膨胀带来的非平凡预测超出了单个场，准单场和多场膨胀的有效现场理论（EFT）的当前状态。与本地EFT相比，非本地$ r^2 $的通货膨胀的一个明显特征是，我们可以在PNG上运行至少更高的数量级。总而言之，通过我们广义的非本地$ r^2 $的通货膨胀，我们获得了强大的通货膨胀框架，可以解释与标量PNG相关的可观察数量的任何检测。
In [1], a most general higher curvature non-local gravity action was derived that admits a particular $R^2$-like inflationary solution predicting the spectral index of primordial scalar perturbations $n_s(N)\approx 1-\frac{2}{N}$, where $N$ is the number of e-folds before the end of inflation, $N\gg 1$, any value of the tensor-to-scalar ratio $r(N)<0.036$ and the tensor tilt $n_t(N)$ violating the $r= -8n_t$ condition. In this paper, we compute scalar primordial non-Gaussianities (PNGs) in this theory and effectively demonstrate that higher curvature non-local terms lead to reduced bispectrum $f_{\rm NL}\left( k_1,\,k_2,\,k_3 \right)$ mimicking several classes of scalar field models of inflation known in the literature. We obtain $\vert f_{\rm NL}\vert \sim O(1-10)$ in the equilateral, orthogonal, and squeezed limits and the running of these PNGs measured by the quantity $\vert\frac{d\ln f_{\rm NL}}{d\ln k}\vert\lesssim 1$. Such PNGs are sufficiently large to be measurable by future CMB and Large Scale Structure observations, thus providing a possibility to probe the nature of quantum gravity. Furthermore, we demonstrate that the $R^2$-like inflation in non-local modification of gravity brings non-trivial predictions which go beyond the current status of effective field theories (EFTs) of single field, quasi-single field and multiple field inflation. A distinguishable feature of non-local $R^2$-like inflation compared to local EFTs is that we can have running of PNGs at least an order of magnitude higher. In summary, through our generalized non-local $R^2$-like inflation, we obtain a robust geometric framework of inflation that can explain any detection of observable quantities related to scalar PNGs.
