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arXiv · 0904.4187

Primordial perturbations and non-Gaussianities in Hořava-Lifshitz gravity

Xian Gao
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Abstract

We investigate primordial perturbations and non-gaussianities in the Hořava-Lifshitz theory of gravitation. In the UV limit, the scalar perturbation in the Hořava theory is naturally scale-invariant, ignoring the details of the expansion of the Universe. One may thus relax the exponential inflation and the slow-roll conditions for the inflaton field. As a result, it is possible that the primordial non-gaussianities, which are ``slow-roll suppressed'' in the standard scenarios, become large. We calculate the non-gaussianities from the bispectrum of the perturbation and find that the equilateral-type non-gaussianity is of the order of unity, while the local-type non-gaussianity remains small, as in the usual single-field slow-roll inflation model in general relativity. Our result is a new constraint on the the Hořava-Lifshitz gravity.

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Xian Gao. 2019-06-25. Primordial perturbations and non-Gaussianities in Hořava-Lifshitz gravity. https://doi.org/10.1088/1674-1137%2F43%2F7%2F075103

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