# Search for sterile neutrinos in holographic dark energy cosmology: Reconciling Planck observation with the local measurement of the Hubble constant

## TL;DR

This study investigates sterile neutrinos within holographic dark energy cosmology using diverse observational data, showing it can better reconcile Planck CMB measurements with local Hubble constant observations and hinting at sterile neutrino existence.

## Contribution

It introduces a holographic dark energy model incorporating sterile neutrinos and demonstrates its effectiveness in resolving the Hubble tension and indicating sterile neutrino presence.

## Key findings

- Holographic dark energy with sterile neutrinos alleviates Hubble tension.
- Evidence suggests sterile neutrinos with N_eff=3.76±0.26.
- Massless or very light sterile neutrinos are favored.

## Abstract

We search for sterile neutrinos in the holographic dark energy cosmology by using the latest observational data. To perform the analysis, we employ the current cosmological observations, including the cosmic microwave background temperature power spectrum data from the Planck mission, the baryon acoustic oscillation measurements, the type Ia supernova data, the redshift space distortion measurements, the shear data of weak lensing observation, the Planck lensing measurement, and the latest direct measurement of $H_0$ as well. We show that, compared to the $\Lambda$CDM cosmology, the holographic dark energy cosmology with sterile neutrinos can relieve the tension between the Planck observation and the direct measurement of $H_0$ much better. Once we include the $H_0$ measurement in the global fit, we find that the hint of the existence of sterile neutrinos in the holographic dark energy cosmology can be given. Under the constraint of the all-data combination, we obtain $N_{\rm eff}= 3.76\pm0.26$ and $m_{\nu,\rm sterile}^{\rm eff}< 0.215\,\rm eV$, indicating that the detection of $\Delta N_{\rm eff}>0$ in the holographic dark energy cosmology is at the $2.75\sigma$ level and the massless or very light sterile neutrino is favored by the current observations.