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Evidence for dark energy equation of state paramater w = -1

  1. Jun 5, 2009 #1
    I'm having trouble finding an article or paper on the observational evidence for dark energy being a cosmological constant. I'm looking at this Living Review by Sean Carroll

    http://relativity.livingreviews.org/Articles/lrr-2001-1/ [Broken]

    and he only describes how supernova data constrain the energy density of DE vs. matter already assuming w = -1.

    How confident are we that w = -1, and which observations suggest this explicitly?
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jun 5, 2009 #2

    Says with combined measurements of Supernovae and Baryon Acoustic Oscillations, assuming constant equation of state: -1.14 < w < -0.88 (table 2)
    Last edited: Jun 6, 2009
  4. Jun 6, 2009 #3


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    There's not really a way to find evidence that w = -1. Rather, we have failed to find evidence that the equation of state parameter is sufficiently different. And, as Amanheis properly points out, the experimental constraints thus far are pretty loose.
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