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Variance and 2 point function in perturbation theory

  1. Feb 9, 2015 #1
    When we try to find the statistical correlation of some perturbation between two positions, we always calculate the quantum 2-point function. Are these two concepts really the same?
    Also, people say vaccum fluctuation is gaussian. For normalized fields, we always use Bunch-Davies initial condition ##\frac{1}{\sqrt{2k}}e^{-i k \tau}##. So in which sense do we say it is gaussian?
    Thanks! Any reference would be appreciated!
  2. jcsd
  3. Feb 10, 2015 #2
    It shouldn't have been moved to quantum physics. It is absolutely cosmology! Cosmological perturbations at very early times of the universe. I should have made it clear in the previous post.
  4. Feb 10, 2015 #3


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    Yes, I too agree that this should be moved back to cosmology.
  5. Feb 10, 2015 #4


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    I think you should try the "Report" button to get attention of somebody from the staff.
  6. Feb 23, 2015 #5
    Still need help. Thanks!
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