CAMB: remove neutrino

Use of Cobaya. camb, CLASS, cosmomc, compilers, etc.
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Dahee Lee
Posts: 16
Joined: April 16 2018
Affiliation: Kyungpook National University

CAMB: remove neutrino

Post by Dahee Lee » June 11 2018

Hi.
I'm a little confused about massless neutrino.
I set the neutrino parameter like this:

omnuh2 = 0.000
massless_neutrinos = 0.0
nu_mass_eigenstates = 0
massive_neutrinos = 0.
share_delta_neff = F
nu_mass_fractions = 0.
nu_mass_degeneracies = 0.

because I want to remove massless and massive neutrinos.
and I checked that massive neutrino's value is zero.
But massless is not.
Although I check that 'CP%Num_Nu_massless' is zero, but for density perturbation and Delta_r/k^2 in transfer.dat output file, massless neutrino has non-zero value.
How can I remove all neutrinos?
Or are massless neutrinos always calculated?

Any help would be appreciated.

Antony Lewis
Posts: 1941
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

Re: CAMB: remove neutrino

Post by Antony Lewis » June 11 2018

The neutrino transfer function may still be calculated even if the actual energy density in neutrinos is zero.

Dahee Lee
Posts: 16
Joined: April 16 2018
Affiliation: Kyungpook National University

CAMB: remove neutrino

Post by Dahee Lee » June 11 2018

Thank you for your replying.

I understood that massless neutrino is calculated even if 'massless_neutrinos' parameter is zero.
Then, is my parameter setting right for removing all neutrinos?
Sorry for my trivial questions.

Antony Lewis
Posts: 1941
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

Re: CAMB: remove neutrino

Post by Antony Lewis » June 12 2018

It looks right, but I haven't tested it.

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