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arXiv · 1908.10663

Primordial non-Gaussianities of scalar and tensor perturbations in general bounce cosmology: Evading the no-go theorem

Shingo Akama·Shin'ichi Hirano·Tsutomu Kobayashi
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Abstract

It has been pointed out that matter bounce cosmology driven by a k-essence field cannot satisfy simultaneously the observational bounds on the tensor-to-scalar ratio and non-Gaussianity of the curvature perturbation. In this paper, we show that this is not the case in more general scalar-tensor theories. To do so, we evaluate the power spectra and the bispectra of scalar and tensor perturbations on a general contracting background in the Horndeski theory. We then discuss how one can discriminate contracting models from inflation based on non-Gaussian signatures of tensor perturbations.

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Shingo Akama, Shin'ichi Hirano, Tsutomu Kobayashi. 2019-08-26. Primordial non-Gaussianities of scalar and tensor perturbations in general bounce cosmology: Evading the no-go theorem. https://doi.org/10.1103/physrevd.101.043529

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