A simple cosmological model with only six parameters ( matter density , \Omega _ { m } h ^ { 2 } , baryon density , \Omega _ { b } h ^ { 2 } , Hubble Constant , H _ { 0 } , amplitude of fluctuations , \sigma _ { 8 } , optical depth , \tau , and a slope for the scalar perturbation spectrum , n _ { s } ) fits not only the three year WMAP temperature and polarization data , but also small scale CMB data , light element abundances , large-scale structure observations , and the supernova luminosity/distance relationship .
Using WMAP data only , the best fit values for cosmological parameters for the power-law flat \Lambda CDM model are ( \Omega _ { m } h ^ { 2 } , \Omega _ { b } h ^ { 2 } ,h,n _ { s } , \tau, \sigma _ { 8 } ) = 0.1277 ^ { +0.0080 } _ { -0 % .0079 } , 0.02229 \pm 0.00073 , 0.732 ^ { +0.031 } _ { -0.032 } , 0.958 \pm 0.016 , 0.089 \pm 0.03 % 0 , 0.761 ^ { +0.049 } _ { -0.048 } ) .
The three year data dramatically shrinks the allowed volume in this six dimensional parameter space .

Assuming that the primordial fluctuations are adiabatic with a power law spectrum , the WMAP data alone require dark matter , and favor a spectral index that is significantly less than the Harrison-Zel ’ dovich-Peebles scale-invariant spectrum ( n _ { s } = 1 ,r = 0 ) .
Adding additional data sets improves the constraints on these components and the spectral slope .
For power-law models , WMAP data alone puts an improved upper limit on the tensor to scalar ratio , r _ { 0.002 } < 0.65 \mbox { ( 95 \% CL ) } and the combination of WMAP and the lensing-normalized SDSS galaxy survey implies r _ { 0.002 } < 0.30 \mbox { ( 95 \% CL ) } .

Models that suppress large-scale power through a running spectral index or a large-scale cut-off in the power spectrum are a better fit to the WMAP and small scale CMB data than the power-law \Lambda CDM model ; however , the improvement in the fit to the WMAP data is only \Delta \chi ^ { 2 } = 3 for 1 extra degree of freedom .
Models with a running-spectral index are consistent with a higher amplitude of gravity waves .

In a flat universe , the combination of WMAP and the Supernova Legacy Survey ( SNLS ) data yields a significant constraint on the equation of state of the dark energy , w = -0.967 ^ { +0.073 } _ { -0.072 } .
If we assume w = -1 , then the deviations from the critical density , \Omega _ { K } , are small : the combination of WMAP and the SNLS data imply \Omega _ { k } = -0.011 \pm 0.012 .
The combination of WMAP three year data plus the HST key project constraint on H _ { 0 } implies \Omega _ { k } = -0.014 \pm 0.017 and \Omega _ { \Lambda } = 0.716 \pm 0.055 .
Even if we do not include the prior that the universe is flat , by combining WMAP , large-scale structure and supernova data , we can still put a strong constraint on the dark energy equation of state , w = -1.08 \pm 0.12 .

For a flat universe , the combination of WMAP and other astronomical data yield a constraint on the sum of the neutrino masses , \sum m _ { \nu } < 0.66 \mbox { eV } \mbox { ( 95 \% CL ) } .
Consistent with the predictions of simple inflationary theories , we detect no significant deviations from Gaussianity in the CMB maps using Minkowski functionals , the bispectrum , trispectrum , and a new statistic designed to detect large-scale anisotropies in the fluctuations .