Running different Dark energy parameterisation

Use of Cobaya. camb, CLASS, cosmomc, compilers, etc.
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ruchika kaushik
Posts: 5
Joined: December 06 2017
Affiliation: research scholar

Running different Dark energy parameterisation

Post by ruchika kaushik » February 04 2018

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?

Antony Lewis
Posts: 1941
Joined: September 23 2004
Affiliation: University of Sussex
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Re: Running different Dark energy parameterisation

Post by Antony Lewis » February 05 2018

You'd need to change the main cosmology equations as well (equations_ppf.f90).

ruchika kaushik
Posts: 5
Joined: December 06 2017
Affiliation: research scholar

Running different Dark energy parameterisation

Post by ruchika kaushik » February 05 2018

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.

Antony Lewis
Posts: 1941
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

Re: Running different Dark energy parameterisation

Post by Antony Lewis » February 06 2018

I suggest you systematically search and check every place where dark energy parameters are used.

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