We study the prospects for detecting neutrino masses from the galaxy angular power spectrum in photometric redshift shells of the Dark Energy Survey ( DES ) over a volume of \sim 20 h ^ { -3 } Gpc ^ { 3 } , combined with the Cosmic Microwave Background ( CMB ) angular fluctuations expected to be measured from the Planck satellite .
We find that for a \Lambda -CDM concordance model with 7 free parameters in addition to a fiducial neutrino mass of M _ { \nu } = 0.24 eV , we recover from DES & Planck the correct value with uncertainty of \pm 0.12 eV ( 95 % CL ) , assuming perfect knowledge of the galaxy biasing .
If the fiducial total mass is close to zero , then the upper limit is 0.11 eV ( 95 % CL ) .
This upper limit from DES & Planck is over 3 times tighter than using Planck alone , as DES breaks the parameter degeneracies in a CMB-only analysis .
The analysis utlilizes spherical harmonics up to 300 , averaged in bin of 10 to mimic the DES sky coverage .
The results are similar if we supplement DES bands ( grizY ) with the VISTA Hemisphere Survey ( VHS ) near infrared band ( JHK ) .
The result is robust to uncertainties in non-linear fluctuations and redshift distortions .
However , the result is sensitive to the assumed galaxy biasing schemes and it requires accurate prior knowledge of the biasing .
To summarize , if the total neutrino mass in nature greater than 0.1eV , we should be able to detect it with DES & Planck , a result with great importance to fundamental Physics .