Ballardini, MarioMaartens, Roy2022-09-202022-09-202022Ballardini, M., & Maartens, R. (2022). Constraining the neutrino mass using a multitracer combination of two galaxy surveys and cosmic microwave background lensing. Monthly Notices of the Royal Astronomical Society, 510(3), 4295-4301. 10.1093/mnras/stab34801365-296610.1093/mnras/stab3480http://hdl.handle.net/10566/7932Measuring the total neutrino mass is one of the most exciting opportunities available with next-generation cosmological data sets. We study the possibility of detecting the total neutrino mass using large-scale clustering in 21 cm intensity mapping and photometric galaxy surveys, together with cosmic microwave background (CMB) information. We include the scale-dependent halo bias contribution due to the presence of massive neutrinos, and use a multitracer analysis in order to reduce cosmic variance. The multitracer combination of an SKAO-MID 21 cm intensity map with stage 4 CMB dramatically shrinks the uncertainty on total neutrino mass to σ(Mν ) 45 meV, using only linear clustering information (kmax = 0.1 h Mpc−1 ) and without a prior on optical depth. When we add to the multitracer the clustering information expected from Legacy Survey of Space and Time, the forecast is σ(Mν ) 12 meV.enNeutrinosCosmologyAstronomyAstrophysicsRadiationArticle