## CMB transfer functions at different redshift from CAMB Python

Use of Healpix, camb, CLASS, cosmomc, compilers, etc.
Thibaut Louis
Posts: 3
Joined: March 31 2011
Affiliation: LAL

### CMB transfer functions at different redshift from CAMB Pytho

Hi,

I was wondering if there is a easy way to get the CMB transfer function at different redshift from CAMB Python.
I'm currently using:
data = camb.get_transfer_functions(pars)
transfer = data.get_cmb_transfer_data()
tf_T=transfer.delta_p_l_k[0,l,:]
to get them at redshift 0.

I guess it should not be too hard to do it directly from CAMB, but any help would be welcome.
Thanks !

Thibaut

Antony Lewis
Posts: 1364
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

### Re: CMB transfer functions at different redshift from CAMB P

You can get the matter transfer functions at different redshifts by calling:

Code: Select all

pars.set_matter_power&#40;redshifts=&#91;0., 0.1,z2,z3&#93;&#41;
There's no way to get the CMB transfer functions at other redshifts.

Thibaut Louis
Posts: 3
Joined: March 31 2011
Affiliation: LAL

### CMB transfer functions at different redshift from CAMB Pytho

Ok thanks !

I thought I could get the code to calculate \Delta_2(k,r) (or \Delta_\ell(k,r)) from equation 13 of:
https://arxiv.org/pdf/1407.5135.pdf
Best,

Thibaut