We consider cosmological models in which Dark Matter (DM) and Dark Energy (DE) are described by a single component, dubbed Unified Dark Matter (UDM) models, in which the DE-like part can have an equation state < −1 at late times without violating the null energy condition. In this paper, we investigate whether this feature can relieve the Hubble tension. We perform a Bayesian analysis of the model using SNIa data from Pantheon, the CMB distance prior from Planck, and the prior on the absolute magnitude M of SNIa from SH0ES. Using the prior, the data suggests a smooth transition taking place at redshifts zt ≃ 2.85, which provides a value H0 = 69.64 ± 0.88 for the Hubble constant, slightly alleviating the tension by ∼1.5σ. Without it, we obtain H0 = 67.6+1.3 −0.82 and a transition happening at zt = 1.36. We also discuss the importance of using the prior on M for constraining this model. © 2024, National University of Ireland Maynooth. All rights reserved.

BAYESIAN ANALYSIS OF A UNIFIED DARK MATTER MODEL WITH TRANSITION: CAN IT ALLEVIATE THE H0 TENSION?

Piattella O. F.
2024-01-01

Abstract

We consider cosmological models in which Dark Matter (DM) and Dark Energy (DE) are described by a single component, dubbed Unified Dark Matter (UDM) models, in which the DE-like part can have an equation state < −1 at late times without violating the null energy condition. In this paper, we investigate whether this feature can relieve the Hubble tension. We perform a Bayesian analysis of the model using SNIa data from Pantheon, the CMB distance prior from Planck, and the prior on the absolute magnitude M of SNIa from SH0ES. Using the prior, the data suggests a smooth transition taking place at redshifts zt ≃ 2.85, which provides a value H0 = 69.64 ± 0.88 for the Hubble constant, slightly alleviating the tension by ∼1.5σ. Without it, we obtain H0 = 67.6+1.3 −0.82 and a transition happening at zt = 1.36. We also discuss the importance of using the prior on M for constraining this model. © 2024, National University of Ireland Maynooth. All rights reserved.
2024
Bayesian methods; cosmic microwave background; Cosmology; Dark Energy; Dark Matter; Hubble tension; supernovae; Unified Dark Matter
Frion, E.; Camarena, D.; Giani, L.; Miranda, T.; Bertacca, D.; Marra, V.; Piattella, O. F.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11383/2178491
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