CosmoMC & CAMB: mpk chi-sq = -Infinity

Use of Cobaya. camb, CLASS, cosmomc, compilers, etc.
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Loison Hoi
Posts: 23
Joined: February 21 2006
Affiliation: McGill University

CosmoMC & CAMB: mpk chi-sq = -Infinity

Post by Loison Hoi » November 13 2006

Hi,

I used WMAP3+SDSS data (May 2006 CosmoMC) with a modified scalar power spectrum. When I included the nonlinear effect in the matter power spectrum, nonlinear_pk = T, the chains would run into regimes which give:

mpk chi-sq: -Infinity

Does anyone know what is wrong?

I tried to output the matter power spectrum, and found it is of order 10^{-20}. However, when I turned off the nonlinear option, nonlinear_pk = F, the magnitude of the matter power spectrum is of order 10^4, so I guess the code for the nonlinear effect breaks down for some models?

Thanks.

Loison Hoi
12 Nov 2006

Loison Hoi
Posts: 23
Joined: February 21 2006
Affiliation: McGill University

CosmoMC & CAMB: mpk chi-sq = -Infinity

Post by Loison Hoi » November 15 2006

I found that halofit.f90 says that:

Only tested for plain LCDM models with power law initial power spectra

Loison Hoi
14 Nov 2006

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