1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted