CAMB vs CMBeasy

Use of Cobaya. camb, CLASS, cosmomc, compilers, etc.
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Ivan Debono
Posts: 25
Joined: April 17 2007
Affiliation: APC, Paris 7 / OBSPM

CAMB vs CMBeasy

Post by Ivan Debono » April 17 2007

Has anyone ever carried out a direct comparison of CMBeasy and CAMB matter power spectra? Should they agree perfectly?

Thanks

Georg Robbers
Posts: 5
Joined: May 23 2006
Affiliation: University of Heidelberg

CAMB vs CMBeasy

Post by Georg Robbers » April 18 2007

Cmbeasy (since v4.0) uses the same normalization as CAMB, so the spectra should be the same. However, be aware that if you use one of the standard *Invariant gauges, what is plotted is actually the gauge invariant [tex]D_g[/tex], so they will differ on very large scales. (See also the discussion here at http://cosmocoffee.info/viewtopic.php?t ... ph+0503277 .)

Ivan Debono
Posts: 25
Joined: April 17 2007
Affiliation: APC, Paris 7 / OBSPM

CAMB vs CMBeasy

Post by Ivan Debono » April 18 2007

Thanks.

I'm actually getting two curves which are slightly offset, especially on large scales, and as far as I can see, I'm using the same cosmological parameters.


Here are the two graphs:
http://sacha.hony.free.fr/fromivan/CMBeasy_vs_camb.pdf

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