Hey,
I need to calculate the covariance of my C_l's at two seperate redshifts. I was told CAMB had a function for this specifically where all I had to do was plug in the two redshifts but after looking through the documentation I cannot seem to find it. Is there such a function? If not what would be the best way for me to complete this task?
The ultimate goal of this is to calculate the Fisher matrix and find the errors on my parameters.
Would love any feedback!
Luca
CAMB: Covariance of Galaxy Count Angular Power Spectrum

 Posts: 5
 Joined: October 06 2023
 Affiliation: UniGe

 Posts: 1973
 Joined: September 23 2004
 Affiliation: University of Sussex
 Contact:
Re: CAMB: Covariance of Galaxy Count Angular Power Spectrum
You can get auto and crossspectra of any number of redshift windows  see box 37 of
https://camb.readthedocs.io/en/latest/CAMBdemo.html
https://camb.readthedocs.io/en/latest/CAMBdemo.html

 Posts: 5
 Joined: October 06 2023
 Affiliation: UniGe
Re: CAMB: Covariance of Galaxy Count Angular Power Spectrum
Thank you for responding! Just so it's clear for me, the "W1XW2" would be the covariance that I am asking for? I would then ask CAMB to extract that array and it would the covariance of my two redshift bins?

 Posts: 1973
 Joined: September 23 2004
 Affiliation: University of Sussex
 Contact:
Re: CAMB: Covariance of Galaxy Count Angular Power Spectrum
Yes (but not to be confused with the covariance of the power spectra of the two bins)