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Homework Help: Event Horizon of Universe

  1. Jan 6, 2010 #1
    1. The problem statement, all variables and given/known data
    Compute the horizon of the universe as a function of [tex]\Omega[/tex]m in a flat universe with both matter and a cosmological constant but no radiation.

    2. Relevant equations

    Event horizon distance
    r = a(t)c [tex]\int_0^tcdt'/a(t')[/tex]

    3. The attempt at a solution

    No idea how i'm going to be able to transform that integral into something I can do,

    Using the FRW equation you can get H2 = [tex]\Lambda/ 3([/tex][tex]\Omega[/tex]m -1)

    possibly using H = (da/dt)/a thus dt = da/aH ?

    and then if you do substitute for an integral in a would the limits be 0 to 1 as we set a = 1 at present or 0 to a?
  2. jcsd
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