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What ideas does the discrepancy of CMB photons affect?

  1. Mar 10, 2010 #1
    An article on news.discovery.com titled, "The Universe is Precisely 13.75 Billion Years Old" on Feb. 4 says:

    "The amount of CMB radiation spotted near clusters of galaxies is greater than expected. According to [cosmological] theory, CMB photons should interact with these clusters, getting kicked to higher energies. WMAP cannot detect these higher energy photons, so there should be a deficit of CMB photons around clusters. This is not the case and scientists will probably be confused by this for some time to come."

    What ideas of cosmological theory might this make us rethink?
    Last edited: Mar 10, 2010
  2. jcsd
  3. Mar 10, 2010 #2


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    For anyone wanting to read the full article it can be found http://news.discovery.com/space/the-universe-is-precisely-1375-billion-years-old.html".

    In answer to your question, it is a bit confusing as this pop-sci article doesn't mention enough specifics to know what it is referring to exactly (i.e. what study has found a discrepancy?). What is being referred to is the Sunyaev-Zel'dovich effect, and we have observed this in clusters (for instance read up on the South Pole Telescope). I'm not completely sure what the latest observational data of the SZ effect says, but I wasn't aware of any glaring discrepancies to date?
    Last edited by a moderator: Apr 24, 2017
  4. Mar 10, 2010 #3
    The WMAP results are not discrepant with other SZ observations. The problem is that the detected signal is 0.5-0.7 times that predicted from simulations, analytical calculations and X-ray observations. The result is more significant for low mass clusters and means we probably don't fully understand the cluster gas.
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