Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Cosmological constant

  1. Jul 15, 2010 #1
    How QFT might possibly explain existence of cosmological constant.
    Does it predict that vacum stress energy tensor has on it's diagonal
    positive time component (density of energy) and negative spatial
    components (preasure=-density)?
     
  2. jcsd
  3. Jul 16, 2010 #2

    Chalnoth

    User Avatar
    Science Advisor

    Well, it does, but it gets the magnitude completely wrong (off by a factor of 10^120).
     
  4. Jul 16, 2010 #3
    Let's forget for a moment about this factor. I'm interested in more general problem.
    Is true at least that vacum stress energy tensor
    has on it's diagonal positive time component (density of energy) and negative spatial
    components (preasure=-density), so that it could play similar role as cosmological
    constant?
     
  5. Jul 16, 2010 #4

    Chalnoth

    User Avatar
    Science Advisor

    If the vacuum has a constant energy density, one that is independent of space and time, then it is a cosmological constant.
     
    Last edited: Jul 16, 2010
  6. Jul 16, 2010 #5
    Thanks
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook