For refcode 2007ApJS..170..377S: Please click here for ADS abstract
NED Abstract
Copyright by American Astronomical Society.
Reproduced by permission
2007ApJS..170..377S
ThreeYear Wilkinson Microwave Anisotropy Probe (WMAP) Observations:
Implications for Cosmology
Spergel, D. N.; Bean, R.; Dore, O.; Nolta, M. R.; Bennett, C. L.; Dunkley,
J.; Hinshaw, G.; Jarosik, N.; Komatsu, E.; Page, L.; Peiris, H. V.; Verde,
L.; Halpern, M.; Hill, R. S.; Kogut, A.; Limon, M.; Meyer, S. S.; Odegard,
N.; Tucker, G. S.; Weiland, J. L.; Wollack, E.; Wright, E. L.
Abstract. 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 3 year WMAP
temperature and polarization data, but also smallscale CMB data, light
element abundances, largescale structure observations, and the supernova
luminosity/distance relationship. Using WMAP data only, the bestfit
values for cosmological parameters for the powerlaw flat Lambda cold dark
matter (LambdaCDM) model are
(Omega_m_h^2^,Omega_b_h^2^,h,n_s_,tau,sigma_8_)=(0.1277^+0.0080^_0.0079_,
0.02229+/0.00073,0.732^+0.031^_0.032_,0.958+/0.016,0.089+/0.030,0.761^
+0.049^_0.048_). The 3 year data dramatically shrink the allowed volume
in this sixdimensional parameter space. Assuming that the primordial
fluctuations are adiabatic with a powerlaw spectrum, the WMAP data alone
require dark matter and favor a spectral index that is significantly less
than the HarrisonZel'dovichPeebles scaleinvariant spectrum (n_s_=1,
r=0). Adding additional data sets improves the constraints on these
components and the spectral slope. For powerlaw models, WMAP data alone
puts an improved upper limit on the tensortoscalar ratio, r_0.002_<0.65
(95% CL) and the combination of WMAP and the lensingnormalized SDSS
galaxy survey implies r_0.002_<0.30 (95% CL). Models that suppress
largescale power through a running spectral index or a largescale cutoff
in the power spectrum are a better fit to the WMAP and smallscale CMB
data than the powerlaw LambdaCDM model; however, the improvement in the
fit to the WMAP data is only Deltachi^2^=3 for 1 extra degree of freedom.
Models with a runningspectral 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 implies Omega_k_=0.011+/0.012. The combination of WMAP 3 year
data plus the HST Key Project constraint on H_0_ implies
Omega_k_=0.014+/0.017 and Omega_Lambda_=0.716+/0.055. Even if we do not
include the prior that the universe is flat, by combining WMAP,
largescale structure, and supernova data, we can still put a strong
constraint on the dark energy equation of state, w=1.08+/0.12. For a
flat universe, the combination of WMAP and other astronomical data yield a
constraint on the sum of the neutrino masses, Sigmam_nu_<0.66 eV (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 largescale anisotropies in the fluctuations.
Key words: Cosmology: Cosmic Microwave Background, Cosmology: Observations
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