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A Equation of state w=1

  1. Dec 21, 2017 #1

    Demystifier

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    A free scalar field with Lagrangian density
    $${\cal L}=\frac{1}{2}g^{\mu\nu}\partial_{\mu}\phi\partial_{\nu}\phi$$
    has the energy momentum tensor with the equation of state ##p=\rho##, i.e. ##w=1##. The Lagrangian density above is a very natural Lagrangian, yet the equation of state ##w=1## seems not to be considered in cosmology. Why is it not considered?
     
    Last edited: Dec 22, 2017
  2. jcsd
  3. Dec 21, 2017 #2

    bapowell

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    I believe ##w=1## is referred to as a "stiff fluid" in the literature. It's been considered, but I don't know how extensively or in what contexts.
     
  4. Dec 21, 2017 #3

    kimbyd

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    What observational puzzles would this solve? Such a fluid would dilute extremely rapidly, with density scaling as ##a^{-6}##.
     
  5. Dec 22, 2017 #4

    Demystifier

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  6. Dec 22, 2017 #5
    Certainly not the matter/antimatter imbalance... I think that is the most important puzzle of way back when. His following link discusses elemental distribution, though.
    Let me know if you find anything on the matter abundances, please!
     
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