Last stand of single small field inflation

摘要: By incorporating both the tensor-to-scalar ratio and measured value of spectral index, we set a bound on solo small field inflation $\Delta \phi / m_{Pl} \geq 1.00 \sqrt{r/0.1}$. Unlike previous bounds which require monotonic $\epsilon_V,$ $|\eta_V| <1$, 60 e-folds inflation, remains valid for non-monotonic $\epsilon_V$, \gtrsim 1$, occurs only over 8 have been observed cosmic microwave background. The negative index is what makes strong; illustrate this by surveying single models finding that $r 0.1$ there no simple potential reproduces CMB perturbations sub-Planckian. Models are sub-Planckian after must be patched together with second epoch fills out remaining $\sim 50$ e-folds. This second, post-CMB characterized extremely $\epsilon_V$ therefore an increasing scalar power spectrum. Using fact large can overabundantly produce primordial black holes, maximum energy level phase inflation.