1
$\begingroup$

Question 1

I was trying to understand why cosmologist calculate the matter fluctuations in spheres of $8 h^{-1} Mpc$. I look for information and I find that in this scale the fluctuations become non-linear, but I can't understand how they conclude that. Why not calculate the matter fluctuations in spheres of $0.8h^{-1} Mpc$?

enter image description here Question 2

Can be explained in a simple way (without calculations) how cosmologist calculate the matter power spectrum? Is the matter power spectrum product of observations or is a theoretical derivation?

$\endgroup$
  • $\begingroup$ The parameter of matter fluctuations in spheres of $8h^{-1} Mpc$ is usually known as $\sigma_{8}$. $\endgroup$ – Nothing Jul 29 at 23:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.