Compartmentalization in the Dark Sector of the Universe after DESI DR2 BAO data

Fuente: arXiv
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Main Authors: van der Westhuizen, Marcel, Figueruelo, David, Thubisi, Rethabile, Sahlu, Shambel, Abebe, Amare, Paliathanasis, Andronikos
Format: Preprint
Published: 2025
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author van der Westhuizen, Marcel
Figueruelo, David
Thubisi, Rethabile
Sahlu, Shambel
Abebe, Amare
Paliathanasis, Andronikos
author_facet van der Westhuizen, Marcel
Figueruelo, David
Thubisi, Rethabile
Sahlu, Shambel
Abebe, Amare
Paliathanasis, Andronikos
contents We consider a non-linear interaction between the dark matter and dark energy components of the universe. In particular, within the FLRW geometry, where dark matter is described by a dust fluid and dark energy by an ideal gas with a constant equation of state parameter, we introduce energy transfer between the two fluids. The effective cosmological fluid leads to a unified dynamical dark energy model with the feature that the Hubble function admits an analytic expression. We study this model using the DESI DR2 Baryonic Acoustic Oscillations data and the Supernova data from Pantheon+. The interacting model fits the data better than the $Λ$CDM model, with $χ_{\text{model}}^{2}-χ_{Λ\text{CDM}}^{2}=-5$. Using the Akaike Information Criterion to compare the two models, we derive $\text{AIC}_{\operatorname{model}}-\text{AIC}_{Λ\text{CDM}}=-1$, from which we conclude that the interacting model is marginally better supported by the data than the $Λ$CDM, but the difference is not statistically significant.
format Preprint
id arxiv_https___arxiv_org_abs_2505_23306
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Compartmentalization in the Dark Sector of the Universe after DESI DR2 BAO data
van der Westhuizen, Marcel
Figueruelo, David
Thubisi, Rethabile
Sahlu, Shambel
Abebe, Amare
Paliathanasis, Andronikos
Cosmology and Nongalactic Astrophysics
We consider a non-linear interaction between the dark matter and dark energy components of the universe. In particular, within the FLRW geometry, where dark matter is described by a dust fluid and dark energy by an ideal gas with a constant equation of state parameter, we introduce energy transfer between the two fluids. The effective cosmological fluid leads to a unified dynamical dark energy model with the feature that the Hubble function admits an analytic expression. We study this model using the DESI DR2 Baryonic Acoustic Oscillations data and the Supernova data from Pantheon+. The interacting model fits the data better than the $Λ$CDM model, with $χ_{\text{model}}^{2}-χ_{Λ\text{CDM}}^{2}=-5$. Using the Akaike Information Criterion to compare the two models, we derive $\text{AIC}_{\operatorname{model}}-\text{AIC}_{Λ\text{CDM}}=-1$, from which we conclude that the interacting model is marginally better supported by the data than the $Λ$CDM, but the difference is not statistically significant.
title Compartmentalization in the Dark Sector of the Universe after DESI DR2 BAO data
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2505.23306