Nine-year wilkinson microwave anisotropy probe (WMAP) observations: Cosmological parameter results

G. Hinshaw, D. Larson, E. Komatsu, D. N. Spergel, C. L. Bennett, J. Dunkley, M. R. Nolta, M. Halpern, R. S. Hill, N. Odegard, L. Page, K. M. Smith, J. L. Weiland, B. Gold, N. Jarosik, A. Kogut, M. Limon, S. S. Meyer, G. S. Tucker, E. WollackE. L. Wright

Research output: Contribution to journalArticle

2807 Scopus citations

Abstract

We present cosmological parameter constraints based on the final nine-year Wilkinson Microwave Anisotropy Probe (WMAP) data, in conjunction with a number of additional cosmological data sets. The WMAP data alone, and in combination, continue to be remarkably well fit by a six-parameter ΛCDM model. When WMAP data are combined with measurements of the high-l cosmic microwave background anisotropy, the baryon acoustic oscillation scale, and the Hubble constant, the matter and energy densities, Ωb h 2, Ωc h 2, and ΩΛ, are each determined to a precision of ∼1.5%. The amplitude of the primordial spectrum is measured to within 3%, and there is now evidence for a tilt in the primordial spectrum at the 5σ level, confirming the first detection of tilt based on the five-year WMAP data. At the end of the WMAP mission, the nine-year data decrease the allowable volume of the six-dimensional ΛCDM parameter space by a factor of 68,000 relative to pre-WMAP measurements. We investigate a number of data combinations and show that their ΛCDM parameter fits are consistent. New limits on deviations from the six-parameter model are presented, for example: the fractional contribution of tensor modes is limited to r < 0.13 (95% CL); the spatial curvature parameter is limited to ; the summed mass of neutrinos is limited to ∑m ν < 0.44 eV (95% CL); and the number of relativistic species is found to lie within N eff = 3.84 ± 0.40, when the full data are analyzed. The joint constraint on N eff and the primordial helium abundance, Y He, agrees with the prediction of standard big bang nucleosynthesis. We compare recent Planck measurements of the Sunyaev-Zel'dovich effect with our seven-year measurements, and show their mutual agreement. Our analysis of the polarization pattern around temperature extrema is updated. This confirms a fundamental prediction of the standard cosmological model and provides a striking illustration of acoustic oscillations and adiabatic initial conditions in the early universe.

Original languageEnglish (US)
Article number19
JournalAstrophysical Journal, Supplement Series
Volume208
Issue number2
DOIs
StatePublished - Oct 2013

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Keywords

  • cosmic background radiation
  • cosmology: observations
  • dark matter
  • early universe
  • instrumentation: detectors
  • space vehicles
  • space vehicles: instruments
  • telescopes

Fingerprint Dive into the research topics of 'Nine-year wilkinson microwave anisotropy probe (WMAP) observations: Cosmological parameter results'. Together they form a unique fingerprint.

  • Cite this

    Hinshaw, G., Larson, D., Komatsu, E., Spergel, D. N., Bennett, C. L., Dunkley, J., Nolta, M. R., Halpern, M., Hill, R. S., Odegard, N., Page, L., Smith, K. M., Weiland, J. L., Gold, B., Jarosik, N., Kogut, A., Limon, M., Meyer, S. S., Tucker, G. S., ... Wright, E. L. (2013). Nine-year wilkinson microwave anisotropy probe (WMAP) observations: Cosmological parameter results. Astrophysical Journal, Supplement Series, 208(2), [19]. https://doi.org/10.1088/0067-0049/208/2/19