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arXiv · 2210.05757

Simple single-field inflation models with arbitrarily small tensor/scalar ratio

Nina K. Stein·William H. Kinney
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Abstract

We construct a family of simple single-field inflation models consistent with Planck / BICEP Keck bounds which have a parametrically small tensor amplitude and no running of the scalar spectral index. The construction consists of a constant-roll hilltop inflaton potential with the end of inflation left as a free parameter induced by higher-order operators which become dominant late in inflation. This construction directly demonstrates that there is no lower bound on the tensor/scalar ratio for simple single-field inflation models.

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Nina K. Stein, William H. Kinney. 2022-10-11. Simple single-field inflation models with arbitrarily small tensor/scalar ratio. https://doi.org/10.1088/1475-7516%2F2023%2F03%2F027

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