CAMB: cmbmain.f90: fixq and density perturbation evolution

Use of Healpix, camb, CLASS, cosmomc, compilers, etc.
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Dahee Lee
Posts: 14
Joined: April 16 2018
Affiliation: Kyungpook National University

CAMB: cmbmain.f90: fixq and density perturbation evolution

Post by Dahee Lee » April 16 2018

Hello.
I'm beginner of CAMB.

I would like to plot density perturbation evolution using cmbmain.f90.
In cmbmain.f90, I use fixq = 0 for computing power spectrum(scalCls.dat).

q is used instead of k in parts of the code (for non-flat models). You can write out whatever you like.

At this sentence, I understood that fixq is k for non-flat model.
So, how can I use it for flat model?
I'm so confused.

For plotting density perturbation evolution, I changed value of fixq(like 1, 0.1, 0.01)
but I think that is non-flat because of changing fixq.

I want to calculate density perturbation evolution and scalCls.dat at the same time.
How can I do for this?


Any help would be appreciated.

Code: Select all

real(dl) :: fixq = 0._dl !Debug output of one q

Code: Select all

!!Example code for plotting out variable evolution
if (fixq/=0._dl) then
tol1=tol/exp(AccuracyBoost-1)
call CreateTxtFile('evolve.txt',1)
do j=1,1000
tauend = taustart+(j-1)*(CP%tau0-taustart)/1000
call GaugeInterface_EvolveScal(EV,tau,y,tauend,tol1,ind,c,w)
yprime = 0
call derivs(EV,EV%ScalEqsToPropagate,tau,y,yprime)
adotoa = 1/(y(1)*dtauda(y(1)))
ddelta= (yprime(3)*grhoc+yprime(4)*grhob)/(grhob+grhoc)
delta=(grhoc*y(3)+grhob*y(4))/(grhob+grhoc)
growth= ddelta/delta/adotoa
write (1,'(7E15.5)') tau, delta, growth, y(3), y(4), y(EV%g_ix), y(1)
end do
close(1)
stop
end if

Antony Lewis
Posts: 1394
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

Re: CAMB: cmbmain.f90: fixq and density perturbation evoluti

Post by Antony Lewis » April 16 2018

I suggest you use the python wrapper, examples in

http://camb.readthedocs.io/en/latest/CAMBdemo.html

Dahee Lee
Posts: 14
Joined: April 16 2018
Affiliation: Kyungpook National University

CAMB: cmbmain.f90: fixq and density perturbation evolution

Post by Dahee Lee » April 17 2018

Thank you very much for your answer.
But I still don't know about fixq for flat model.
Is it right that changing fixq(like 1, 0.1, 0.01) is non-flat?

Any help would be appreciated.

Antony Lewis
Posts: 1394
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

Re: CAMB: cmbmain.f90: fixq and density perturbation evoluti

Post by Antony Lewis » April 18 2018

q=k in a flat model.

Dahee Lee
Posts: 14
Joined: April 16 2018
Affiliation: Kyungpook National University

CAMB: cmbmain.f90: fixq and density perturbation evolution

Post by Dahee Lee » April 18 2018

Thank you. I got it.
That question was my misunderstanding.

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