Constraining neutrino mass using the large-scale H i distribution in the post-reionization epoch

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 h 21 cm observation distributed equally over 25 radio pointings and a Lyman alpha forest survey with 30 quasars lines of sights in 1deg(2), allows us to measure Omega(nu) at a 3.25 per cent level. A total of 25 000 h radio-interferometric observation distributed equally over 25 radio pointings and a Lyman alpha survey with (n) over bar = 60deg(-2) will allow Omega(nu) to be measured at a 2.26 per cent level. This corresponds to an idealized measurement of am(nu) at the precision of (100 +/- 2.26)meV and f(nu) = Omega(nu)/Omega(m) at 2.49 per cent level.