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PLanck results live here

  1. Mar 20, 2013 #1
  2. jcsd
  3. Mar 20, 2013 #2
    Should be good thanks for the link
     
  4. Mar 20, 2013 #3
    I think you can ask questions at the ocnfernce via twitter #AskPlanck
     
  5. Mar 20, 2013 #4
    No major rumours yet = no major discoveries to leak?
     
  6. Mar 21, 2013 #5

    Chalnoth

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    The papers are out tomorrow, it looks like. I'm a bit worried at the discussion of anomalies in the press release.
     
  7. Mar 21, 2013 #6
    Try here:
    http://www.sciops.esa.int/index.php?project=PLANCK&page=Planck_Published_Papers [Broken]
     
    Last edited by a moderator: May 6, 2017
  8. Mar 21, 2013 #7
    From the paper: "Scientific results include robust support
    for the standard, six parameter  lambda CDM model of cosmology and improved measurements for the parameters that define this model, including a
    highly significant deviation from scale invariance of the primordial power spectrum. The Planck values for some of these parameters and others
    derived from them are significantly di erent from those previously determined. Several large scale anomalies in the CMB temperature distribution
    detected earlier by WMAP are confirmed with higher confidence. Plancksets new limits on the number and mass of neutrinos, and has measured
    gravitational lensing of CMB anisotropies at 25. Planck finds no evidence for non-Gaussian statistics of the CMB anisotropies. There is some
    tension between Planck and WMAP results; this is evident in the power spectrum and results for some of the cosmology parameters. In general,
    Planck results agree well with results from the measurements of baryon acoustic oscillations"
     
  9. Mar 21, 2013 #8

    Chalnoth

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    Ahh, thanks. Glad they at least released the pre-prints (or most of them anyway), even if the publication date isn't until tomorrow.
     
    Last edited by a moderator: May 6, 2017
  10. Mar 21, 2013 #9
    – The Planck best-fit model is in excellent agreement with the
    most current BAO data. However, it requires a Hubble constant
    that is significantly lower (67 km s1 Mpc1) than expected
    from traditional measurement techniques, raising the
    possibility of systematic e ects in the latter.
    – An exploration of parameter space beyond the basic set leads
    to: (a) firmly establishing the e ective number of relativistic
    species (neutrinos) at 3; (b) constraining the flatness of
    space-time to a level of 0.1%; (c) setting significantly improved
    constraints on the total mass of neutrinos, the abundance
    of primordial Helium, and the running of the spectral
    index of the power spectrum.
    – we find no evidence at the current level of analysis for tensor
    modes, nor for a dynamical form of dark energy, nor for time
    variations of the fine structure constant.
    – we find some tension between the amplitude of matter fluctuations
    (8) derived from CMB data and that derived from
    Sunyaev-Zeldovich data; we attribute this tension to uncertainties
    in cluster physics that a ect the latter.
    – we find important support for single-field slow-roll inflation
    via our constraints on running of the spectral index, curvature
    and fNL.
    – The Planck data squeezes the region of the allowed standard
    inflationary models, preferring a concave potential: power
    law inflation, the simplest hybrid inflationary models, and
    simple monomial models with n > 2, do not provide a good
    fit to the data.
    – we find no evidence for statistical deviations from isotropy
    at ` >50, to very high precision.
    – we do find evidence for deviations from isotropy at low `s.
    In particular, we find a coherent deficit of power with respect
    to our best-fit CDMmodel at `s between 20 and 30.
    – We confirm the existence of the so-called WMAP anomalies
     
  11. Mar 21, 2013 #10

    Chalnoth

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    Some initial thoughts:
    1. I find it interesting that they used an extremely conservative method to obtain the estimate of the power spectrum: they only used three of the nine frequency bands, and used masks which cut out around half of the sky. So there is a lot of untapped data left on the floor there that can be teased out using better component separation (the higher and lower frequencies aren't terribly useful for getting better CMB data, but can be used to reduce the size of the sky masks used). They probably took this route because they were worried about systematic effects.

    This, ultimately, may be why they didn't release polarization results: they didn't trust their component separation enough, and component separation is absolutely required for polarization results.

    2. They definitively detected the low quadrupole at the same amplitude as WMAP, which means it is indeed real. But it's also not significant compared to cosmic variance, so there's still no way to say that it means anything of significance.

    3. There's a solid detection of [itex]n_s < 1[/itex], which is good news for inflation.

    4. No spatial curvature detected, with an accuracy of [itex]\pm 0.007[/itex] when combined with BAO.

    So all in all, it's mostly just better measurements of what we knew before.
     
  12. Mar 21, 2013 #11
    Thanks for the link going to take me a bit to read the articles,
     
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