Constraining Neutrino mass using the large scale HI distribution in the Post-reionization epoch

TL;DR

This paper explores how the large-scale distribution of neutral hydrogen after reionization can be used to measure the total neutrino mass by analyzing the suppression of power in the matter power spectrum through cross-correlation of 21 cm signals and Lyman-alpha forest data.

Contribution

It demonstrates the potential of combining 21 cm observations with Lyman-alpha forest surveys to constrain neutrino mass with high precision using Fisher matrix analysis.

Findings

Neutrino mass can be measured at 3.25% precision with 10,000 hrs of 21 cm data and 30 quasar lines.

Improved measurement precision of 2.26% with 25,000 hrs of data and higher quasar density.

Potential to determine the sum of neutrino masses with an accuracy of about 2 meV.

Abstract

The neutral intergalactic medium in the post reionization epoch allows us to study cosmological structure formation through the observation of the redshifted 21 cm signal and the Lyman-alpha forest. We investigate the possibility of measuring the total neutrino mass through the suppression of power in the matter power spectrum. We investigate the possibility of measuring the neutrino mass through its imprint on the cross-correlation power spectrum of the 21-cm signal and the Lyman-alpha forest. We consider a radio-interferometric measurement of the 21 cm signal with a SKA1-mid like radio telescope and a BOSS like Lyman-alpha forest survey. A Fisher matrix analysis shows that at the fiducial redshift z = 2.5, a 10,000 hrs 21-cm observation distributed equally over 25 radio pointings and a Lyman-alpha forest survey with 30 quasars lines of sights in 1 {deg}^2, allows us to measure \Omega_{\nu} at a 3.25 % level. A total of 25,000 hrs radio-interferometric observation distributed equally over 25 radio pointings and a Lyman-alpha survey with \bar n = 60 {\rm deg}^{-2} will allow \Omega_{\nu} to be measured at a 2.26 % level. This corresponds to an idealized measurement of \sum m_{\nu} at the precision of (100 \pm 2.26) meV and f_{\nu}= \Omega_{\nu}/ \Omega_{m} at 2.49 % level.