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arXiv · 1504.05839

Inflationary models with non-minimally derivative coupling

Nan Yang·Qin Fei·Qing Gao·Yungui Gong
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Abstract

We derive the general formulae for the the scalar and tensor spectral tilts to the second order for the inflationary models with non-minimally derivative coupling without taking the high friction limit. The non-minimally kinetic coupling to Einstein tensor brings the energy scale in the inflationary models down to be sub-Planckian. In the high friction limit, the Lyth bound is modified with an extra suppression factor, so that the field excursion of the inflaton is sub-Planckian. The inflationary models with non-minimally derivative coupling are more consistent with observations in the high friction limit. In particular, with the help of the non-minimally derivative coupling, the quartic power law potential is consistent with the observational constraint at 95\% CL.

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Nan Yang, Qin Fei, Qing Gao, Yungui Gong. 2015-04-22. Inflationary models with non-minimally derivative coupling. https://doi.org/10.1088/0264-9381%2F33%2F20%2F205001

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