## [CosmoMC] - changed nrun convention?

Use of Healpix, camb, CLASS, cosmomc, compilers, etc.
Ira *Wolfson
Posts: 64
Joined: January 24 2013
Affiliation: BGU
Contact:

### [CosmoMC] - changed n_run convention?

Hi,

My old rig has fallen, so I just finished basically formatting everything and reinstalling CosmoMC (and all deps).

I have now run 3 separate runs with the different datasets.

Just as a reference:

Code: Select allp>

#general settings
#Bicep-Keck-Planck, varying cosmological parameters
DEFAULT&#40;batch2/BKPlanck.ini&#41;

#Planck 2015, default just include native likelihoods &#40;others require clik&#41;
#DEFAULT&#40;batch2/plik_dx11dr2_HM_v18_TT.ini&#41;
DEFAULT&#40;batch2/lowTEB.ini&#41;
DEFAULT&#40;batch2/lowl.ini&#41;
DEFAULT&#40;batch2/lensing.ini&#41;

#Other Likelihoods
#DEFAULT&#40;batch2/BAO.ini&#41;
#DEFAULT&#40;batch2/WiggleZ_MPK.ini&#41;
#DEFAULT&#40;batch2/MPK.ini&#41;
#DEFAULT&#40;batch2/WL.ini&#41;

#general settings
DEFAULT&#40;batch2/common.ini&#41;

#e.g. to vary r in addition to standard 6&#58;
#&#40;for r>0 also need compute_tensors=T&#41;
compute_tensors = T
param&#91;r&#93; = 0.06 0.0 0.5 0.04 0.04
param&#91;logA&#93; = 3.1 1.5 4.5 0.04 0.04
param&#91;ns&#93; = 0.96 0.9 1.05 0.04 0.04
param&#91;nrun&#93;=−0.09 −0.5 0.5 0.04 0.04
param&#91;nrunrun&#93;=0
param&#91;tau&#93;=0.07
#limits&#91;r02&#93;=0 N
limits&#91;r&#93;=0 N


I used different data sets - including BAO, Wigglez etc.

The results for $n_{run}$ are always slightly positive, where in my previous experience, when $n_{run}$ is used (and $n_{run,run}$ is set to 0 ) , one usually gets a slightly negative value.

This is also the case with the most recent Planck collaboration analysis.

Has the convention for CosmoMC changed between the last stable version and the current master branch?

If not, any advise on what is happening?

Thanks

– Ira

Antony Lewis
Posts: 1354
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

### Re: [CosmoMC] - changed n_run convention?

As far as I know nothing has changed (could check by compare outputs for non-trivial initial nrun using action=4 for last stable versus master).