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arXiv · 1408.6839

The Lyth Bound of Inflation with a Tilt

Juan Garcia-Bellido·Diederik Roest·Marco Scalisi·Ivonne Zavala
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Abstract

We provide strong evidence for universality of the inflationary field range: given an accurate measurement of $(n_s,r)$, one can infer $Δϕ$ in a model-independent way in the sub-Planckian regime for a range of universality classes of inflationary models. Both the tensor-to-scalar ratio as well as the spectral tilt are essential for the field range. Given the Planck constraints on $n_s$, the Lyth bound is strengthened by two orders of magnitude: whereas the original bound gives a sub-Planckian field range for $r \lesssim 2 \cdot 10^{-3}$, we find that $n=0.96$ brings this down to $r \lesssim 2 \cdot 10^{-5}$.

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Juan Garcia-Bellido, Diederik Roest, Marco Scalisi, Ivonne Zavala. 2015-01-08. The Lyth Bound of Inflation with a Tilt. https://doi.org/10.1103/physrevd.90.123539

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