Oh that clears up part i for me. Thanks guys! My answer for part i comes to a=2.8*10^-4
Is that right?
I am confused about the method we have been asked to use for part ii.
Do i just plug in the value of a into the (da)^2 = Ho^2/a^2 equation and solve for 't' ?
Am I missing something...
Ive understood the concept of how I'm supposed to do it. But, I am confused on how to start the radiation equation. As in what formula do I use to find the scale factor for a radiation dominated universe?
(i) Obtain the scale factor a(t) and redshift z when the energy density of matter and radiation were equal.
(ii) Next use the a(t) relation for a matter-only universe to estimate the time of matter-radiation equality.
(iii) Repeat (ii) but using the a(t) relation for a radiation-only universe...