Recent content by MykDee

If you call a the expansion factor, the energy density of the radiation goes as \rho_{rad}\propto a^{-4}, while for the matter you have \rho_{mat}\propto a^{-3}. If you plot logarithmically these quantities, you will see that at a certain a_{eq} the two densities will be equal: there it is the...

I agree with you, and indeed this is what I would do if I'm asked something like "how do you calculate mathematically the power spectrum?". My answer would be: I know the primordial P(k), a power law with spectral index n = 1, and I also know the form of the transfer function (that goes to 0 for...

Ok, thank you. Now, suppose that I've measured the C_l and then the P(k). This power spectrum is valid also for the galaxies? I mean, the P(k) calculated via CMB, does represent both the large and the small structures in the Universe, or for those structure (like galaxies or cluster of galaxies)...

Hi all! It's my first post, but I follow this forum since a couple of years. Now I have a big question for you: how to measure the CDM (or \LambdaCDM) power spectrum (better, the variance \propto k^3 P(k)) from the observations? What parameters are necessary?