Constraining sterile neutrino and dark energy with the latest cosmological observations [CEA]

http://arxiv.org/abs/1706.06913


We investigate how the dark energy properties change the cosmological limits on sterile neutrino parameters by using recent cosmological observations. We consider the simplest dynamical dark energy models, the $w$CDM model and the holographic dark energy (HDE) model to make an analysis. The cosmological observations used in this work include the Planck 2015 temperature and polarization data, the baryon acoustic oscillation data, the type Ia supernova data, the Hubble constant direct measurement data, and the CMB lensing measurement. We find that, $m_{\nu,{\rm{sterile}}}^{\rm{eff}}<0.2675$ eV and $N_{\rm eff}<3.5718$ for $\Lambda$CDM cosmology, $m_{\nu,{\rm{sterile}}}^{\rm{eff}}<0.5313$ eV and $N_{\rm eff}<3.5008$ for $w$CDM cosmology, and $m_{\nu,{\rm{sterile}}}^{\rm{eff}}<0.1989$ eV and $N_{\rm eff}<3.6701$ for HDE cosmology, under the constraints of the combination of these data. Thus, without the addition of measurements of growth of structure, only upper limits on both $m_{\nu,{\rm{sterile}}}^{\rm{eff}}$ and $N_{\rm eff}$ can be derived, indicating that no evidence of the existence of a sterile neutrino with eV-scale mass is found in this analysis. Moreover, compared to the $\Lambda$CDM model, in the $w$CDM model the limit on $m_{\nu,{\rm{sterile}}}^{\rm{eff}}$ becomes much looser, but in HDE model the limit becomes much tighter. Therefore, the dark energy properties could significantly impact the constraint limits on sterile neutrino parameters. Furthermore, we also show that, compared to the $\Lambda$CDM cosmology, the dynamical dark energy cosmology with sterile neutrinos can relieve the tension between the Planck observation and the direct measurement of $H_0$ much better.

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L. Feng, J. Zhang and X. Zhang
Thu, 22 Jun 17
60/68

Comments: 17 pages, 5 figures. arXiv admin note: substantial text overlap with arXiv:1703.04884