Non-Gaussianities in generalized non-local R2-like inflation

In [1], a most general higher curvature non-local gravity action was derived that admits 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 number e-folds before end inflation, $N\gg 1$, any value tensor-to-scalar ratio $r(N)<0.036$ and tensor tilt $n_t(N)$ violating $r= -8n_t$ condition. this paper, we compute non-Gaussianities (PNGs) in theory effectively demonstrate terms lead to reduced bispectrum $f_{\rm NL}\left( k_1,\,k_2,\,k_3 \right)$ mimicking several classes field models inflation known literature. We obtain $\vert f_{\rm NL}\vert \sim O(1-10)$ equilateral, orthogonal, squeezed limits running these PNGs measured by quantity $\vert\frac{d\ln NL}}{d\ln k}\vert\lesssim 1$. Such are sufficiently large be measurable future CMB Large Scale Structure observations, thus providing possibility probe nature quantum gravity. Furthermore, modification brings non-trivial predictions which go beyond current status effective theories (EFTs) single field, quasi-single multiple inflation. A distinguishable feature compared local EFTs can have at least an order magnitude higher. summary, through our generalized robust geometric framework explain detection observable quantities related PNGs.