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arXiv · 1611.05062

UV completion of the Starobinsky model, tensor-to-scalar ratio, and constraints on non-locality

James Edholm
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Abstract

In this paper, we build upon the successes of the ultraviolet (UV) completion of the Starobinsky model of inflation. This involves an extension of the Einstein-Hilbert term by an infinite covariant derivative theory of gravity, which is quadratic in curvature. It has been shown that such a theory can potentially resolve the cosmological singularity for a flat, homogeneous and isotropic geometry, and now it can also provide a successful cosmological inflation model, which in the infrared matches all the predictions of the Starobinsky model of inflation. The aim of this note is to show that the tensor-to-scalar ratio is modified by the scale of non-locality, and in general a wider range of tensor-to-scalar ratios can be obtained in this class of model, which can put a lower bound on the scale of non-locality for the first time as large as the O$(10^{14})$ GeV.

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James Edholm. 2016-11-15. UV completion of the Starobinsky model, tensor-to-scalar ratio, and constraints on non-locality. https://doi.org/10.1103/physrevd.95.044004

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