## Running different Dark energy parameterisation

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

### Running different Dark energy parameterisation

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+&#40;1.-a&#41;*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: 1394
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

### Re: Running different Dark energy parameterisation

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

As per as what I understood, changing this following part of equation_ppf.f90 will serve our purpose.

Code: Select all

function w_de&#40;a&#41;
...
if&#40;.not. use_tabulated_w&#41; then
w_de=w_lam+wa_ppf*&#40;1._dl-a&#41;
...
end function w_de

â€Œ
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.