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Dark energy @ standard rulers

  1. Mar 21, 2008 #1

    wolram

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    Gold Member

    Has any one read this paper?

    Shifting the Universe: Early Dark Energy and Standard Rulers
    Authors: Eric V. Linder, Georg Robbers
    Comments: 6 pages, 3 figures
    Subjects: Astrophysics (astro-ph)

    The presence of dark energy at high redshift influences both the cosmic sound horizon and the distance to last scattering of the cosmic microwave background. We demonstrate that through the degeneracy in their ratio, early dark energy can lie hidden in the CMB temperature and polarization spectra, leading to an unrecognized shift in the sound horizon. If the sound horizon is then used as a standard ruler, as in baryon acoustic oscillations, then the derived cosmological parameters can be nontrivially biased. Fitting for the absolute ruler scale (just as supernovae must be fit for the absolute candle magnitude) removes the bias but decreases the leverage of the BAO technique by a factor 2.
     
    Last edited: Mar 21, 2008
  2. jcsd
  3. Mar 21, 2008 #2
    Link: http://arxiv.org/abs/0803.2877

    Submitted two days ago. I did a quick read. My interest in cosmology is fairly limited. What I have learned is geared more as a testing ground for physics. One of the reasons I insist on separating the model from the empirical content. I see nothing really surprising in that paper though.
     
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