WMAP DR4 Release Notes for the Cosmological Parameters Table

The data made available through this page has been updated. The most recent version of this data may be accessed through https://lambda.gsfc.nasa.gov/product/wmap/current/"

  • Seven-Year Parameters Table
    • 18 November 2010
      • Six additional sets of parameter chains were released for three models (ΛCDM+MNU, ΛCDM+NREL, and WCDM) and two data sets (WMAP and WMAP+H0). Version 4.1 of the WMAP likelihood software and RECFAST 1.5 were used.
    • 15 January 2010
      • The fourth data release parameters table.

  • Five-Year Parameters Table
    • 18 March 2008
      • Updated secondary parameters for models containing massive neutrinos. The initial release had an error in the derivation of the Hubble constant for these models (of order 2 km/s/Mpc), so secondary parameters that depend on H0 had a small error.
    • February 2008
      • The third data release parameters table.

  • Three-Year Parameters Table
    • 25 January 2007
      • The best-fit matter power spectra, P(k), are provided for all the supported model/dataset combinations in the table. Each of these files has two columns. The first column is k/h in units of Mpc-1. The second column is the linear matter power spectrum P(k), defined such that the variance is:
        σ2 = (2π)-3 ∫d3k P(k)
    • 12 January 2007
      • Three of the four new chains (lcdm/all, lcdm+sz=0/wmap, m2phi2/wmap) were updated by adding a constant offset to the log likelihood to bring them into agreement with the convention adopted with the other chains.
    • 10 January 2007
      • All of the entries were updated with better-converged chains in mid-2006. These are denoted "v2p1" chains in the Table. The results of this reprocessing did not materially affect any cosmological conclusions.
      • The following table entries have been updated with new parameter values and chains to reflect the changes in the low-l likelihood and the point source correction. These are denoted "v2p2" in the Table entries.
        • lcdm/wmap
        • lcdm/all
        • lcdm+sz=0/wmap
        • m2phi2/wmap (new)

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