CAMB: "DebugEvolution" parameter

Use of Healpix, camb, CLASS, cosmomc, compilers, etc.
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gongbo zhao
Posts: 69
Joined: January 04 2005
Affiliation: ICG, Portsmouth

CAMB: \"DebugEvolution\" parameter

Post by gongbo zhao » March 22 2005

Dear all:
Does anybody know the meaning of the "DebugEvolution" parameter in modules.f90 ? I have set it as .true. and found nothing has changed in CAMB results except for the timing.(The timing of the whole cmbmain is 4.366624 compared with 2.037888 in the .false . case) .What did CAMB do in the (4.366624-2.037888)s? :)


Antony Lewis
Posts: 1413
Joined: September 23 2004
Affiliation: University of Sussex

Re: CAMB: \\\"DebugEvolution\\\" parameter

Post by Antony Lewis » March 22 2005

It forces all the modes to evolve to today. It is a very good approximation for a CMB-only calculation to stop evolution shortly after recombination on small scales, which is why switching it on makes no difference.

It's useful if you want to write out the full evolution on small scales for a paper plot, and for testing purposes. Turning on CMB lensing or transfer functions has a similar effect.

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