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xzackli / Bolt.jl

differentiable boltzmann code
MIT License
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Difference between \rho_P0, \rho_\sigma, and \rho0\scrM #47

Closed jmsull closed 3 years ago

jmsull commented 3 years ago

As mentioned in #44, I noticed something weird when plotting perturbations.

When normalizing the massive neutrino perturbations for plotting I normalize by the value of the \rho_\sigma function (from perturbations.jl) acting on a vector of all ones at the particular redshift.

I find that this is the same as the density I get from the background spline (bg.\rho0\scrM) of the background \rho_P0 function.

However when I call the background \rhoP0 function from the plotting script I get a different value than the one returned by \rho\sigma *a^-4 and the spline (both of which have the same value). I find this especially weird since \rho_P0 is what is used to generate the spline.

Not sure if this issue will affect the evolution, but I will look into it more carefully.

jmsull commented 3 years ago

This was due to a lazy typo 🤦 Closing this