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Unit transformation of Cosmological Constant ?

  1. Oct 6, 2009 #1
    Question : How to unit transformation of Cosmological Constant?

    10-47 GeV4 ===> ? eV
    or, x eV ===> ? GeV4

    1) How compair ( X ) GeV4 with ( Y ) eV ?

    2) How compair ( 10-29 g/cm3) with (Y eV)?

    please, easely explain to me!
    and, have a nice day!
    Last edited: Oct 6, 2009
  2. jcsd
  3. Oct 6, 2009 #2
    Try these conversions. They are a good tool when working with cosmology equations like scalar field inflation models.

    Temperature: 1 GeV ---> 10^13 K
    Mass: 1 GeV ---> 10^-25 g
    Time: 1 GeV^-1 ---> 10^-24 sec
    Length: 1 GeV^-1 ---> 10^-14 cm
  4. Oct 7, 2009 #3
    Thanks you!
    I will try by them.

    If reader have a better idea, please write down!
  5. Oct 9, 2009 #4
    You are comparing energies with energydensities. eV is of dimension energy.
    But if c=hbar=1 (cosmologists tend to redefine their units like that), lenght and time have the same dimension, that is they are both of dimension energy^-1.

    Thus, energy densities (energy/Length^3) have the same dimension as energy^4.
  6. Oct 9, 2009 #5
    Thanks Amanheis! good explain!

    I have make a challenge to that fine tuning problem(the reason of that mass density of universe close to critical mass density), inflation mechanism(start and end), the reason of that dark energy has a small value, future of our universe, at Physics Forums Blog.
    Last edited: Oct 9, 2009
  7. Oct 11, 2009 #6
    I got a solution
    Last edited: Oct 12, 2009
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