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Main Author: Miranda, Marcello
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2405.08071
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author Miranda, Marcello
author_facet Miranda, Marcello
contents This study explores the feasibility of an effective Friedmann equation in removing the classical Big Bang initial singularity and replacing it with a non-singular bounce occurring at a critical energy density value. In a spatially flat, homogeneous, and isotropic universe, the effective theory is obtained by introducing a function that is parametrically dependent on the critical energy density. This function measures the deviation from the benchmark theory, which is recovered as the critical energy density approaches infinity. Focusing on the covariant single-field formulation in viable Horndeski gravity, our analysis shows that both the effective and the benchmark theories belong to the same scalar-tensor theory, without any additional propagating degrees of freedom: the cuscuton and extended cuscuton models.
format Preprint
id arxiv_https___arxiv_org_abs_2405_08071
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Covariant single-field formulation of effective cosmological bounces
Miranda, Marcello
General Relativity and Quantum Cosmology
This study explores the feasibility of an effective Friedmann equation in removing the classical Big Bang initial singularity and replacing it with a non-singular bounce occurring at a critical energy density value. In a spatially flat, homogeneous, and isotropic universe, the effective theory is obtained by introducing a function that is parametrically dependent on the critical energy density. This function measures the deviation from the benchmark theory, which is recovered as the critical energy density approaches infinity. Focusing on the covariant single-field formulation in viable Horndeski gravity, our analysis shows that both the effective and the benchmark theories belong to the same scalar-tensor theory, without any additional propagating degrees of freedom: the cuscuton and extended cuscuton models.
title Covariant single-field formulation of effective cosmological bounces
topic General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2405.08071