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Interacting dark-matter dark energy

Posted: April 15 2019
by srijita sinha
Hi,

I am new to CAMB. I never did any serious calculations using Fortran as I use Mathematica. This question may have already been asked, but I cannot find it. Please pardon me. I will be grateful if you help me out.

I have interacting dark matter dark energy perturbation equations in conformal Newtonian gauge. The EoS parameter for dark energy w_{de} is not a constant but depends on the redshift, z. Other background quantities are also evolving with redshift.

My questions are:
(a) Do I have to change my equations into the synchronous gauge?
(b) Do I need to change the GuageInterface module of equations.f90 for my equations?
(c) How do I incorporate the varying background in the code?
(d) Where do I put the initial conditions?
(e) How to do these if I want to use pyCAMB?

Thank you a lot in advance.


Srijita

Re: Interacting dark-matter dark energy

Posted: April 16 2019
by Antony Lewis
a,b: yes. c and d are also implemented in equations.f90.

Once you have modified the fortran, using the python version should be straightforward, you'll just need to add any new parameters to CAMBparams in both fortran and the python wrapper.

Re: Interacting dark-matter dark energy

Posted: April 26 2019
by srijita sinha
Thanks a lot, Sir. I want to apologise in advance for the dumb question.

I managed to implement (a), (b) and (d). But cannot understand how and where to implement (c).
For reference: I want to implement Eq. No. 2.20 and 2.21 of https://arxiv.org/abs/1204.6135. I want to know how do I change the CAMB for the Interacting Holographic models there.

I am sorry if this has been already discussed and I missed it.