Interacting ultralight dark matter and dark energy and fits to cosmological data in a field theory approach

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Hauptverfasser: Aboubrahim, Amin, Nath, Pran
Format: Preprint
Veröffentlicht: 2024
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author Aboubrahim, Amin
Nath, Pran
author_facet Aboubrahim, Amin
Nath, Pran
contents The description of dark matter as a pressure-less fluid and of dark energy as a cosmological constant, both minimally coupled to gravity, constitutes the basis of the concordance $Λ\text{CDM}$ model. However, the concordance model is based on using equations of motion directly for the fluids with constraints placed on their sources, and lacks an underlying Lagrangian. In this work, we propose a Lagrangian model of two spin zero fields describing dark energy and dark matter with an interaction term between the two along with self-interactions. We study the background evolution of the fields as well as their linear perturbations, suggesting an alternative to $Λ$CDM with dark matter and dark energy being fundamental dynamical fields. The parameters of the model are extracted using a Bayesian inference tool based on multiple cosmological data sets which include those of Planck (with lensing), BAO, Pantheon, SH0ES, and WiggleZ. Using these data, we set constraints on the dark matter mass and the interaction strengths. Furthermore, we find that the model is able to alleviate the Hubble tension for some data sets while also resolving the $S_8$ tension.
format Preprint
id arxiv_https___arxiv_org_abs_2406_19284
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Interacting ultralight dark matter and dark energy and fits to cosmological data in a field theory approach
Aboubrahim, Amin
Nath, Pran
Cosmology and Nongalactic Astrophysics
High Energy Physics - Phenomenology
The description of dark matter as a pressure-less fluid and of dark energy as a cosmological constant, both minimally coupled to gravity, constitutes the basis of the concordance $Λ\text{CDM}$ model. However, the concordance model is based on using equations of motion directly for the fluids with constraints placed on their sources, and lacks an underlying Lagrangian. In this work, we propose a Lagrangian model of two spin zero fields describing dark energy and dark matter with an interaction term between the two along with self-interactions. We study the background evolution of the fields as well as their linear perturbations, suggesting an alternative to $Λ$CDM with dark matter and dark energy being fundamental dynamical fields. The parameters of the model are extracted using a Bayesian inference tool based on multiple cosmological data sets which include those of Planck (with lensing), BAO, Pantheon, SH0ES, and WiggleZ. Using these data, we set constraints on the dark matter mass and the interaction strengths. Furthermore, we find that the model is able to alleviate the Hubble tension for some data sets while also resolving the $S_8$ tension.
title Interacting ultralight dark matter and dark energy and fits to cosmological data in a field theory approach
topic Cosmology and Nongalactic Astrophysics
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2406.19284