Alleviating cosmological tensions with a hybrid dark sector
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arXiv
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| Autori principali: | , , , , |
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| Natura: | Preprint |
| Pubblicazione: |
2024
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| author | Teixeira, Elsa M. Poulot, Gaspard van de Bruck, Carsten Di Valentino, Eleonora Poulin, Vivian |
| author_facet | Teixeira, Elsa M. Poulot, Gaspard van de Bruck, Carsten Di Valentino, Eleonora Poulin, Vivian |
| contents | We investigate a cosmological model inspired by hybrid inflation, where two scalar fields representing dark energy (DE) and dark matter (DM) interact through a coupling that is proportional to the DE scalar field $1/ϕ$. The strength of the coupling is governed solely by the initial condition of the scalar field, $ϕ_i$, which parametrises deviations from the standard $Λ$CDM model. In this model, the scalar field tracks the behaviour of DM during matter-domination until it transitions to DE while the DM component decays quicker than standard CDM during matter-domination, and is therefore different from some interacting DM-DE models which behaves like phantom dark energy. Using \textit{Planck} 2018 CMB data, DESI BAO measurements and Pantheon+ supernova observations, we find that the model allows for an increase in $H_0$ that can help reduce the Hubble tension. In addition, we find that higher values of the coupling parameter are correlated with lower values of $ω_m$, and a mild decrease of the weak-lensing parameter $S_8$, potentially relevant to address the $S_8$ tension. Bayesian model comparison, however, reveals inconclusive results for most datasets, unless S$H_0$ES data are included, in which case a moderate evidence in favour of the hybrid model is found. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2412_14139 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Alleviating cosmological tensions with a hybrid dark sector Teixeira, Elsa M. Poulot, Gaspard van de Bruck, Carsten Di Valentino, Eleonora Poulin, Vivian Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology High Energy Physics - Theory We investigate a cosmological model inspired by hybrid inflation, where two scalar fields representing dark energy (DE) and dark matter (DM) interact through a coupling that is proportional to the DE scalar field $1/ϕ$. The strength of the coupling is governed solely by the initial condition of the scalar field, $ϕ_i$, which parametrises deviations from the standard $Λ$CDM model. In this model, the scalar field tracks the behaviour of DM during matter-domination until it transitions to DE while the DM component decays quicker than standard CDM during matter-domination, and is therefore different from some interacting DM-DE models which behaves like phantom dark energy. Using \textit{Planck} 2018 CMB data, DESI BAO measurements and Pantheon+ supernova observations, we find that the model allows for an increase in $H_0$ that can help reduce the Hubble tension. In addition, we find that higher values of the coupling parameter are correlated with lower values of $ω_m$, and a mild decrease of the weak-lensing parameter $S_8$, potentially relevant to address the $S_8$ tension. Bayesian model comparison, however, reveals inconclusive results for most datasets, unless S$H_0$ES data are included, in which case a moderate evidence in favour of the hybrid model is found. |
| title | Alleviating cosmological tensions with a hybrid dark sector |
| topic | Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology High Energy Physics - Theory |
| url | https://arxiv.org/abs/2412.14139 |