Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations:
  Cosmological Interpretation
  (Abridged) The 7-year WMAP data and improved astrophysical data rigorously
test the standard cosmological model and its extensions. By combining WMAP with
the latest distance measurements from BAO and H0 measurement, we determine the
parameters of the simplest LCDM model. The power-law index of the primordial
power spectrum is n_s=0.968+-0.012, a measurement that excludes the
scale-invariant spectrum by 99.5%CL. The other parameters are also improved
from the 5-year results. Notable examples of improved parameters are the total
mass of neutrinos, sum(m_nu)<0.58eV, and the effective number of neutrino
species, N_eff=4.34+0.86-0.88. We detect the effect of primordial helium on the
temperature power spectrum and provide a new test of big bang nucleosynthesis.
We detect, and show on the map for the first time, the tangential and radial
polarization patterns around hot and cold spots of temperature fluctuations, an
important test of physical processes at z=1090 and the dominance of adiabatic
scalar fluctuations. With the 7-year TB power spectrum, the limit on a rotation
of the polarization plane due to potential parity-violating effects has
improved to Delta(alpha)=-1.1+-1.4(stat)+-1.5(syst) degrees. We report
significant detections of the SZ effect at the locations of known clusters of
galaxies. The measured SZ signal agrees well with the expected signal from the
X-ray data. However, it is a factor of 0.5 to 0.7 times the predictions from
"universal profile" of Arnaud et al., analytical models, and hydrodynamical
simulations. We find, for the first time in the SZ effect, a significant
difference between the cooling-flow and non-cooling-flow clusters (or relaxed
and non-relaxed clusters), which can explain some of the discrepancy. This
lower amplitude is consistent with the lower-than-theoretically-expected SZ
power spectrum recently measured by the South Pole Telescope collaboration.
