Public repository of the Cosmic Linear Anisotropy Solving System (master for the most recent version of the standard code; GW_CLASS to include Cosmic Gravitational Wave Background anisotropies; classnet branch for acceleration with neutral networks; ExoCLASS branch for exotic energy injection; class_matter branch for FFTlog)
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How is a_eq() calculated with nonzero m_ncdm? #490
I am trying to determine how exactly a_eq() is being calculated in the case of nonzero m_ncdm. In background.c I found that
a_eq = Omega_r/Omega_m with Omega_r = Omega0_g (1. + 3.044 7./8.*pow(4./11.,4./3.)) and Omega_m = Omega0_b + Omega0_cdm. This treatment assumes that any massive neutrinos are light enough that they are relativistic at equality, and background.c notes that this needs to be generalized later on. As I increase m_ncdm, I find that the a_eq computed by Class deviates more and more from the a_eq formula given in background.c. Could someone please point me to the way a_eq is calculated with massive neutrinos that are not fully relativistic at equality?
Hi all,
I am trying to determine how exactly a_eq() is being calculated in the case of nonzero m_ncdm. In background.c I found that a_eq = Omega_r/Omega_m with Omega_r = Omega0_g (1. + 3.044 7./8.*pow(4./11.,4./3.)) and Omega_m = Omega0_b + Omega0_cdm. This treatment assumes that any massive neutrinos are light enough that they are relativistic at equality, and background.c notes that this needs to be generalized later on. As I increase m_ncdm, I find that the a_eq computed by Class deviates more and more from the a_eq formula given in background.c. Could someone please point me to the way a_eq is calculated with massive neutrinos that are not fully relativistic at equality?
Thank you very much in advance.