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Running different Dark energy parameterisation

Posted: February 04 2018
by ruchika kaushik
By adding param[w] and param[wa] with its appropriate prior, cosomomc will run for w0waCDM. But now I want to change the equation of state to some other dark energy parameterization, say 7CPL. Where 7CPL equation of state is defined as,
w(a) = w_0 + w_a (1-a)^7
I found the definition of equation of state at line 1916

Code: Select all

w_de_hm=cosm%w+(1.-a)*cosm%wa

in halo_ppf.f90. If I am customizing this definition according to 7CPL, does it run for 7CPL or do I need to change something else?

Re: Running different Dark energy parameterisation

Posted: February 05 2018
by Antony Lewis
You'd need to change the main cosmology equations as well (equations_ppf.f90).

Running different Dark energy parameterisation

Posted: February 05 2018
by ruchika kaushik
Thank you very much for your reply.
As per as what I understood, changing this following part of equation_ppf.f90 will serve our purpose.

Code: Select all

function w_de(a)
...
    if(.not. use_tabulated_w) then
       w_de=w_lam+wa_ppf*(1._dl-a)
...
end function w_de

‌
Should I change any variables like quintessence or w_xx?

So after changing the equations in both these files, Will it be running for 7CPL?
Or there any other changes in any other file are also required.
Thanks in advance.

Re: Running different Dark energy parameterisation

Posted: February 06 2018
by Antony Lewis
I suggest you systematically search and check every place where dark energy parameters are used.