Hi,
I'm trying to get familiar with using CAMB, so I would like to figure out its details with only a simple cosmological model where there are only matter, dark matter, and photons. I managed to remove massive neutrinos by setting mnu=0 in camb.CAMBparams.set_cosmology(). But I couldn't find a parameter that lets me to remove the massless neutrinos. Is it possible to remove the massless neutrino component in using CAMB? If yes, how can it be done?
Thanks!
Rui
CAMB: Setting massless neutrino density to zero
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Re: CAMB: Setting massless neutrino density to zero
You can try setting nnu=0 (not sure it will work; not you also change BBN predictions if messing with number of neutrinos).
Antony
Antony
Re: CAMB: Setting massless neutrino density to zero
Thank you for the reply. Yes, I tried to set nnu=0 or/and standard_neutrino_neff=0, but I still get nonzero delta_neutrino using get_time_evolution(). I guess the effect of neutrino is small and I probably can just ignore it at the moment.
Regards,
Rui
Regards,
Rui
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- Posts: 1980
- Joined: September 23 2004
- Affiliation: University of Sussex
- Contact:
Re: CAMB: Setting massless neutrino density to zero
It will still evolve the fractional perturbations, but the contribution to the evolution should go to zero (because weighed by the background densities)
Re: CAMB: Setting massless neutrino density to zero
Okay, that makes sense. Thanks for the explanation!