Recent content by bolahab

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    Evidence for dark matter and why it's not baryonic

    Yeah for this question i did a lot of work on it, but I am trying to see what i got is right, and if does match what i get from you guys
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    Maximum He-4 fraction with neutron lifetime 89 s and Q-value 0.129 MeV

    yes it is transformed into He-3, that was all the info from the question, but the rest info as it says in the book when it is transformed into He-3
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    Maximum He-4 fraction with neutron lifetime 89 s and Q-value 0.129 MeV

    Suppose the neutron decay time n was 89 sec. AND the difference in rest mass between neutron to proton, Qn, was 0.129 MeV. What would the maximum Helium fraction, Yp, be?
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    Evidence for dark matter and why it's not baryonic

    Why do we think there is a significant amount of Dark Matter in the universe? a) Descibe at least 3 independent situations which require Dark Matter to understand observations. b) Why don’t we think that Dark Matter is baryonic? c) What do we think is might be?
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    Finding Ωm and time until the universe doubles in size

    Thnx George that really helped, but can you please give more details ?
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    Finding Ωm and time until the universe doubles in size

    Yeah it can be expressed like that
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    Finding Ωm and time until the universe doubles in size

    Hey guys, can someone please help with this question. We now live in a time when the energy balance of the universe is dominated by Λ. A long time from now, at t2× the universe will have doubled in size, i.e.: a(t2×) = 2. At present, radiation is negligible: Ωr,0 ~ 0, and will remain so...
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