Neutrinos and dark energy constraints from future galaxy surveys and CMB lensing information

TL;DR

This paper uses Fisher matrix forecasts to show how future galaxy surveys and CMB lensing can significantly improve constraints on neutrino masses and dark energy parameters, highlighting the importance of lensing information.

Contribution

It demonstrates the substantial improvements in parameter constraints achievable with future galaxy surveys and CMB lensing, emphasizing the necessity of including lensing in precision cosmology.

Findings

CMB lensing improves neutrino parameter constraints by 93% with Planck.

Euclid survey enhances neutrino constraints by approximately 128%.

Including lensing in future CMB experiments increases the FoM by a factor of 6.

Abstract

We explore the possibility of obtaining better constraints from future astronomical data by means of the Fisher information matrix formalism. In particular, we consider how cosmic microwave background (CMB) lensing information can improve our parameter error estimation. We consider a massive neutrino scenario and a time-evolving dark energy equation of state in the $\Lambda$CDM framework. We use Planck satellite experimental specifications together with the future galaxy survey Euclid in our forecast. We found improvements in almost all studied parameters considering Planck alone when CMB lensing information is used. In this case, the improvement with respect to the constraints found without using CMB lensing is of 93% around the fiducial value for the neutrino parameter. The improvement on one of the dark energy parameter reaches 4.4%. When Euclid information is included in the analysis, the improvements on the neutrino parameter constraint is of approximately 128% around its fiducial value. The addition of Euclid information provides smaller errors on the dark energy parameters as well. For Euclid alone, the FoM is a factor of $\sim$ 29 higher than that from Planck alone even considering CMB lensing. Finally, the consideration of a nearly perfect CMB experiment showed that CMB lensing cannot be neglected specially in more precise future CMB experiments since it provided in our case a 6 times better FoM in respect to the unlensed CMB analysis .