Natural inflation with natural number of e-foldings

Abstract

We examine natural inflation without the use of the standard slow-roll approximation by considering the number of physical e-folds $\ln (a_e{H}_e/aH)$. We show that $\tilde{H}=aH\propto \cos (A\varphi /2{)}^{2/A^2}\sin (A\varphi /2)$ produces a natural inflationary scenario. This model may be solved exactly, showing that the slow-roll approximation overestimates the tensor-to-scalar ratio by about $13-19\%$ for $n_s\approx 0.96$ and $50-60$ $e$-folds.

References in corpus (3)

• Natural Inflation: Consistency with Cosmic Microwave Background Observations of Planck and BICEP2
• General bounds in Hybrid Natural Inflation
• Inflationary e-folding and the implications for gravitational-wave detection

Cited by in corpus (4)

• Cosmological constraints on slow-roll inflation: an update
• Natural Inflation with non minimal coupling to gravity in $R^2$ gravity under the Palatini formalism
• The reheating constraints to natural inflation in Horndeski gravity
• Finite inflation in curved space