Dear Antony,
I hope this message finds you well.
I was trying to perform some calculations with CAMB by introducing a variation of the 𝑁_eff parameter (ΔNeff). In the "Neutrinos and Dark Radiation" sections, specifically subsection 3 of the CAMB notes under "further examples," there are instructions in the last paragraph:
Consider 2 massless active and 1 massive active neutrino all at the standard temperature (3.046/3)1/4Tν, where the massive active neutrino has mi = 0.06eV and hence contributes Ωaνh^2 = 0.00064. If there is also one sterile (at a different temperature) contributing ∆Neff to the total so that Neff = 3.046 + ∆Neff, and the total density parameter Ωνh^2 = 0.00064 + Ωsνh^2, then use: share delta neff = F, massless neutrinos = 2.0307, nu mass eigenstates = 2, massive neutrinos = 1 1, nu mass degeneracies = 1.0153 ∆Neff, nu mass fractions = X Y where X =0.00064/Ωνh^2 and Y = Ωsνh^2/Ωνh^2.
However, I am unsure how to incorporate the density parameters specified there, and also the way that massive neutrinos have to be written (massive neutrinos = 1 1), are those 1 separate by spacing? Because in this format the code give us an error (it could be because we choose arbitrary values for the density parameters as well).
My aim is to achieve something similar to what is done in this paper: https://arxiv.org/pdf/1606.09199.
Thank you for your assistance.
Best regards,
Clara
I hope this message finds you well.
I was trying to perform some calculations with CAMB by introducing a variation of the 𝑁_eff parameter (ΔNeff). In the "Neutrinos and Dark Radiation" sections, specifically subsection 3 of the CAMB notes under "further examples," there are instructions in the last paragraph:
Consider 2 massless active and 1 massive active neutrino all at the standard temperature (3.046/3)1/4Tν, where the massive active neutrino has mi = 0.06eV and hence contributes Ωaνh^2 = 0.00064. If there is also one sterile (at a different temperature) contributing ∆Neff to the total so that Neff = 3.046 + ∆Neff, and the total density parameter Ωνh^2 = 0.00064 + Ωsνh^2, then use: share delta neff = F, massless neutrinos = 2.0307, nu mass eigenstates = 2, massive neutrinos = 1 1, nu mass degeneracies = 1.0153 ∆Neff, nu mass fractions = X Y where X =0.00064/Ωνh^2 and Y = Ωsνh^2/Ωνh^2.
However, I am unsure how to incorporate the density parameters specified there, and also the way that massive neutrinos have to be written (massive neutrinos = 1 1), are those 1 separate by spacing? Because in this format the code give us an error (it could be because we choose arbitrary values for the density parameters as well).
My aim is to achieve something similar to what is done in this paper: https://arxiv.org/pdf/1606.09199.
Thank you for your assistance.
Best regards,
Clara
Statistics: Posted by Clara Rojas — July 12 2024