Starting from the dynamic dark energy definition w(a) = w_0 + (1-a)*w_a, where w_0 is the current value and w_a is the variation of the equation-of-state with scale factor a, I have been trying to modify the dark energy parameters of the initial (w_0, w_a) parametrisation. I want to use a pivot scale a_p and the related equation-of-state parameter w_p = w(a_p) to define the initial parameter w_a via the equation w_a = (w_p - w_0)/(1 - a_p). For a starter, I have defined the ´dark_energy_model: ppf´ in the .yaml file and have then also added the parameters w_p and a_p to the parameter list of the .yaml file, as shown here below:
Code: Select all
...
params:
w:
prior:
min: -3
max: 1
ref:
dist: norm
loc: -0.99
scale: 0.02
proposal: 0.02
latex: w_{0,\mathrm{DE}}
wp:
prior:
min: -3
max: 2
ref:
dist: norm
loc: 0
scale: 0.05
proposal: 0.05
latex: w_{p,\mathrm{DE}}
ap: 0.8333 # fixed 1/1.2!
wa:
derived: 'lambda w, wp, ap: (wp-w)/(1-ap)'
min: -3
max: 2
latex: w_\mathrm{a}
we:
derived: 'lambda w, wa: w+wa'
min: -6
max: 0
latex: w_\mathrm{e}
...
I assumed that this would be enough to incorporate the new parameters into the calculation but it was not successful.
Then I read from the CAMB Input parameter model that "To add a new parameter, add it to the CAMBparams type in model.f90, then edit the _fields_ list in the CAMBparams class in model.py to add the new parameter in the corresponding location of the member list. After rebuilding the python version you can then access the parameter by using params.new_parameter_name where params is a CAMBparams instance." So I tried changing both the model.f90 and model.py file, as described above together with the modified .yaml file but was still unsuccessful.
Can you please advise me how this should be done?
Do I need to make further changes in some file like the DarkEnergyInterface.f90, DarkEnergyPPF.f90, or dark_energy.py?
Thank you very much in advance,
Marianne Talvitie