Probing neutrino masses with CMB lensing extraction

Abstract

We evaluate the ability of future cosmic microwave background (CMB) experiments to measure the power spectrum of large scale structure using quadratic estimators of the weak lensing deflection field. We calculate the sensitivity of upcoming CMB experiments such as BICEP, QUaD, BRAIN, ClOVER and Planck to the nonzero total neutrino mass ${M}_{\ensuremath{\nu}}$ indicated by current neutrino oscillation data. We find that these experiments greatly benefit from lensing extraction techniques, improving their one-sigma sensitivity to ${M}_{\ensuremath{\nu}}$ by a factor of order four. The combination of data from Planck and the SAMPAN mini-satellite project would lead to $\ensuremath{\sigma}({M}_{\ensuremath{\nu}})\ensuremath{\sim}0.1$ eV, while a value as small as $\ensuremath{\sigma}({M}_{\ensuremath{\nu}})\ensuremath{\sim}0.035$ eV is within the reach of a space mission based on bolometers with a passively cooled 3--4 m aperture telescope, representative of the most ambitious projects currently under investigation. We show that our results are robust not only considering possible difficulties in subtracting astrophysical foregrounds from the primary CMB signal but also when the minimal cosmological model ($\ensuremath{\Lambda}$ Mixed Dark Matter) is generalized in order to include a possible scalar tilt running, a constant equation-of-state parameter for the dark energy and/or extra relativistic degrees of freedom.