A Single Field Inflation Model with Large Local Non-Gaussianity

Abstract

A detection of large local form non-Gaussianity is considered to be able to rule out all single field inflation models. This statement is based on a single field consistency condition. Despite the awareness of some implicit assumptions in the derivation of this condition and the demonstration of corresponding examples that illustrate these caveats, to date there is still no explicit and self-consistent model which can serve as a counterexample to this statement. We present such a model in this Letter.

Figures (2)

• Figure 1: Inflaton $\phi$ versus inflationary $e$-fold $n$. The upper solid black curve and the lower solid blue curve represent the undershoot and overshoot case, respectively. The dashed lines are the analytic ansatz for the non-attractor phase. Parameters are $V_0 \simeq 6 \times 10^{-4}$, $M=5 \times 10^{-5}$, $\alpha = 10$ and $\eta = -6$, ($M_P \equiv 1$).
• Figure 2: Phase diagram for the same model as in Fig. \ref{['phin']}. Dashed blue and dashed-dotted red curves represent the undershoot and overshoot case, respectively. The black solid curve is the separator of different types of trajectories.