Hi,
We have found a nonzero signal for Clkg, up to 10% of the b=1 case at very low l (<20), even when b=0 in Cambsources. An example script is on github here:
https://github.com/akrolewski/cambources_test/blob/main/example_for_cosmo_coffee.py
(the repo includes the text file for the dN/dz as well). This signal appears whether I set nonlinear=True or False, and doesn't appear to be affected by the Limber parameters either. Do you know what might be going on?
Alex Krolewski
Nonzero Clkg from CambSources at very low ell even when b=0
-
- Posts: 11
- Joined: November 07 2019
- Affiliation: UC Berkeley
-
- Posts: 1945
- Joined: September 23 2004
- Affiliation: University of Sussex
- Contact:
Re: Nonzero Clkg from CambSources at very low ell even when b=0
I think this is because the "counts" source term is defined in the Newtonian gauge. Bias affects the synchronous-gauge density, so the Newtonian one is non-zero (if very small) on large scales even with bias=0. See Eq 31 of http://arxiv.org/abs/1105.5292
-
- Posts: 11
- Joined: November 07 2019
- Affiliation: UC Berkeley
Re: Nonzero Clkg from CambSources at very low ell even when b=0
Thanks, that clears it up!