Combining measurements of the galaxy power spectrum and the cosmic microwave background ( CMB ) is a powerful means of constraining the summed mass of neutrino species \sum m _ { \nu } , but is subject to systematic uncertainties due to non-linear structure formation , redshift-space distortions and galaxy bias .
We empirically test the robustness of neutrino mass results to these effects by separately analyzing power spectra of red and blue galaxies from the Sloan Digital Sky Survey ( SDSS-II ) Data Release 7 ( DR7 ) , combined with the CMB five-year Wilkinson Microwave Anisotropy Probe ( WMAP5 ) data .
We consider fitting for a range of maximum wavenumber k using twelve different galaxy bias models .
For example , using a new model based on perturbation theory and including redshift space distortions ( ) , the all-galaxy power spectrum combined with WMAP5 for a wavenumber range of k < 0.2 h { Mpc } ^ { -1 } yields 95 % CL \sum m _ { \nu } < 0.46 eV .
The red and blue galaxy power spectra give 0.41 and 0.63 eV respectively for this model .
Using mock catalogues , we find the expected difference in these limits assuming a true neutrino mass of zero is 0.10 \pm 0.14 eV .
Thus the difference of 0.22 eV between upper limits on neutrino mass for red and blue galaxies is approximately 1 \sigma from the expected value .
We find similar results for the other models and k ranges tested .
This indicates good agreement for current data but hints at possible issues for next-generation surveys .
Being able to perform such systematic tests is advantageous , and future surveys would benefit by including broad galaxy populations and luminosities that enable such a decomposition .