Minimal dark energy: key to sterile neutrino and Hubble constant tensions?

TL;DR

Minimal dark energy models, with the same number of parameters as the standard model, can potentially resolve tensions related to sterile neutrino masses and the Hubble constant, aligning cosmological and laboratory observations.

Contribution

This paper demonstrates that minimal dark energy models can simultaneously alleviate the sterile neutrino mass tension and the Hubble constant discrepancy.

Findings

Sterile neutrino mass bounds are consistent with short-baseline experiments.

Minimal dark energy models significantly reduce the Hubble tension.

PEDE scenario is favored over ΛCDM with full data sets.

Abstract

Minimal dark energy models, described by the same number of free parameters of the standard cosmological model with cold dark matter plus a cosmological constant to parameterize the dark energy component, constitute very appealing scenarios which may solve long-standing, pending tensions. On the one hand, they alleviate significantly the tension between cosmological observations and the presence of one sterile neutrino motivated by the short-baseline anomalies: we obtain a $95\%$ CL cosmological bound on the mass of a fully thermalized fourth sterile neutrino ($N_{\rm eff}=4$) equal to $m_s<0.65\ (1.3)$~eV within the PEDE (VM) scenarios under consideration. Interestingly, these limits are in agreement with the observations at short-baseline experiments, and the PEDE scenario is favored with respect to the $\Lambda$CDM case when the full data combination is considered. On the other hand, the Hubble tension is satisfactorily solved in almost all the minimal dark energy schemes explored here. These phenomenological scenarios may therefore shed light on differences arising from near and far universe probes, and also on discrepancies between cosmological and laboratory sterile neutrino searches.