Towards testing the general bounce cosmology with the CMB B-mode auto-bispectrum

Fuente: arXiv
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Auteurs principaux: Akama, Shingo, Orlando, Giorgio, Delgado, Paola C. M.
Format: Preprint
Publié: 2024
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author Akama, Shingo
Orlando, Giorgio
Delgado, Paola C. M.
author_facet Akama, Shingo
Orlando, Giorgio
Delgado, Paola C. M.
contents It has been shown that a three-point correlation function of tensor perturbations from a bounce model in general relativity with a minimally-coupled scalar field is highly suppressed, and the resultant three-point function of cosmic microwave background (CMB) B-mode polarizations is too small to be detected by CMB experiments. On the other hand, bounce models in a more general class with a non-minimal derivative coupling between a scalar field and gravity can predict the three-point correlation function of the tensor perturbations without any suppression, the amplitude of which is allowed to be much larger than that in general relativity. In this paper, we evaluate the three-point function of the B-mode polarizations from the general bounce cosmology with the non-minimal coupling and show that a signal-to-noise ratio of the B-mode auto-bispectrum in the general class can reach unity for $\ell_{\rm max}\geq9$ and increase up to $5.39$ for $\ell_{\rm max}=100$ in the full-sky case. We also discuss the possibility to test the general class of bounce models by upcoming CMB experiments.
format Preprint
id arxiv_https___arxiv_org_abs_2404_14393
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Towards testing the general bounce cosmology with the CMB B-mode auto-bispectrum
Akama, Shingo
Orlando, Giorgio
Delgado, Paola C. M.
Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
High Energy Physics - Theory
It has been shown that a three-point correlation function of tensor perturbations from a bounce model in general relativity with a minimally-coupled scalar field is highly suppressed, and the resultant three-point function of cosmic microwave background (CMB) B-mode polarizations is too small to be detected by CMB experiments. On the other hand, bounce models in a more general class with a non-minimal derivative coupling between a scalar field and gravity can predict the three-point correlation function of the tensor perturbations without any suppression, the amplitude of which is allowed to be much larger than that in general relativity. In this paper, we evaluate the three-point function of the B-mode polarizations from the general bounce cosmology with the non-minimal coupling and show that a signal-to-noise ratio of the B-mode auto-bispectrum in the general class can reach unity for $\ell_{\rm max}\geq9$ and increase up to $5.39$ for $\ell_{\rm max}=100$ in the full-sky case. We also discuss the possibility to test the general class of bounce models by upcoming CMB experiments.
title Towards testing the general bounce cosmology with the CMB B-mode auto-bispectrum
topic Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
High Energy Physics - Theory
url https://arxiv.org/abs/2404.14393