Difference between revisions of "Cosmological Parameters"

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{{DISPLAYTITLE: 2015 Cosmological parameters and MC chains}}
 
== Description ==
 
== Description ==
  
The cosmological parameter results explore a variety of cosmological models with combinations of Planck and other data. We provide results from MCMC exploration chains, as well as best fits, and sets of parameter tables. Definitions, conventions and reference are contained in <cite>#planck2013-p11</cite>.  
+
The 2015 cosmological parameter results explore a variety of cosmological models with combinations of Planck and other data. We provide results from MCMC exploration chains, as well as best fits, and sets of parameter tables. Definitions, conventions and reference are contained in {{PlanckPapers|planck2013-p11}} {{PlanckPapers|planck2014-a15||Planck-2015-A15}}.
  
 
==Production process==
 
==Production process==
  
Parameter chains are produced using CosmoMC, a sampling package available from [http://cosmologist.info/cosmomc]. This includes the sample analysis package GetDist, and the scripts for managing, analysing, and plotting results from the full grid or runs. Chain products provided here have had burn in removed. Some results with additional data are produced by importance sampling.
+
Parameter chains are produced using CosmoMC, a sampling package available [http://cosmologist.info/cosmomc here]. This includes the sample analysis package (and GUI) GetDist, and the scripts for managing, analysing, and plotting results from the full grid or runs. Chain products provided here have had burn in removed. Some results with additional data are produced by importance sampling.
  
 
Note that the baseline model includes one massive neutrino (0.06eV). Grid outputs include WMAP 9 results for consistent assumptions.
 
Note that the baseline model includes one massive neutrino (0.06eV). Grid outputs include WMAP 9 results for consistent assumptions.
Line 11: Line 12:
 
== Caveats and known issues ==
 
== Caveats and known issues ==
  
Confidence intervals are derived from the MCMC samples, and assume the input likelihoods are exactly correct, so there is no quantification for systematic errors other than via the covariance, foreground and beam error models assumed in the likelihood codes. We had some issues producing reliable results from the minimizer used to produce the best fits, so in some cases the quoted fits may be significantly improved. The chain outputs contain some parameters that are not used, for example the beam mode ranges for all but the first mode (the beam modes are marginalised over anlaytically internally to the likelihood).
+
# Confidence intervals are derived from the MCMC samples, and assume the input likelihoods are exactly correct, so there is no quantification for systematic errors other than via the covariance, foreground and beam error models assumed in the likelihood codes.  
 +
# Non-linear lensing modelling uses Halofit; for some extended models and CMB lensing only analyses, tails of the chains may be away from the domain of validity.
 +
# The CAMB version used for most results is Dec 2014; the Jan 2015 version is used for lensing-only models with neutrinos, and only differs in the neutrino corrections to the Halofit model.
 +
# There is evidence of temperature-polarization leakage that may affect results including high-L polarization; hence use caution in the interpretation of results including polarization
 +
# Alternative CamSpec likelihood results in the tables are generated using a slightly older CosmoMC version, with fewer derived parameters and a slightly different BBN predictions for the helium abundance.
  
 
== Related products ==
 
== Related products ==
  
Results of the parameter exploration runs should be reproducible using CosmoMC with the Planck likelihood code.
+
Results of the baseline parameter exploration runs should be reproducible using CosmoMC with the Planck 2015 likelihood codes (when available).
  
 
== Parameter Tables ==
 
== Parameter Tables ==
  
These list paramter constraints for each considered model and data combination separately
+
These list parameter constraints for each considered model and data combination separately. For the baseline likelihood see
  
* PDF tables with 68% limits [[File:grid_limit68.pdf]]
+
* PDF tables with 68% limits [[Media:baseline_params_table_2015_limit68.pdf]]
* PDF tables with 95% limits [[File:grid_limit95.pdf]]
+
* PDF tables with 95% limits [[Media:baseline_params_table_2015_limit95.pdf]]
  
There are also summary comparison tables, showing how constraints for selected models vary with data used to constrain them:
+
There are also larger files including alternative CamSpec and DetSet likelihood results, along with shifts in parameters compared to baseline in units of the baseline error:
  
* Comparison tables with 68% limits [[File:comparetables_limit68.pdf]]
+
* PDF tables with 68% limits [[Media:params_table_2015_limit68.pdf]]
* Comparison tables with 95% limits [[File:comparetables_limit95.pdf]]
+
* PDF tables with 95% limits [[Media:params_table_2015_limit95.pdf]]
  
  
Data combination tags used to label results are as follows (see <cite>#planck2013-p11</cite> for full description and references):
+
Data combination tags used to label results are as follows (see {{PlanckPapers|planck2013-p11}} for full description and references):
  
  
{| class="wikitable"  align="center" style="text-align:left" border="1" cellpadding="5" cellspacing="0"  
+
{| class="wikitable"  align="center" style="text-align:left" border="1" cellpadding="3" cellspacing="0" width=800px
 
|+  
 
|+  
 +
|- bgcolor="ffdead"       
 
! Tag|| Data
 
! Tag|| Data
 
|-
 
|-
| '''planck''' || high-L Planck temperature (CamSpec, 50 <= l <= 2500)
+
| '''plikHM''' || baseline high-L Planck power spectra (plik cross half-mission, 30 <= l <= 2508)
 
|-
 
|-
| '''lowl''' || low-L: Planck  temperature (2 <= l <= 49)
+
| '''plikDS''' || high-L Planck power spectra (plik cross detsets, 30 <= l <= 2508)
 +
|-
 +
| '''CamSpecHM''' || high-L Planck power spectra (CamSpec cross half-mission, 30 <= l <= 2500)
 +
|-
 +
| '''CamSpecDS''' || high-L Planck power spectra (CamSpec cross detsets, 30 <= l <= 2500)
 +
|-
 +
| '''lowl''' || low-L: Planck  temperature only (2 <= l <= 29)
 +
|-
 +
| '''lowTEB''' ||  low-L temperature and LFI polarization (2 <= l <= 29)
 +
|-
 +
| '''lowEB''' ||  low-L LFI polarization only (2 <= l <= 29)
 +
|-
 +
| '''WMAPTEB''' ||  low-L temperature, and  LFI+WMAP polarization (2 <= l <= 29)
 
|-
 
|-
 
| '''lensing''' || Planck lensing power spectrum reconstruction
 
| '''lensing''' || Planck lensing power spectrum reconstruction
 
|-
 
|-
| '''lowLike''' || low-L WMAP 9 polarization  (WP)
+
| '''lensingonly''' || Planck lensing power spectrum reconstruction only; T,E fixed to best-fit spectrum + priors
 +
|-
 +
| '''BKP''' || The Bicep-Keck-Planck fiducial B mode likelihood
 +
|-
 +
| '''zre6p5''' || A hard prior z_re > 6.5
 +
|-
 +
| '''tau07''' || A Gaussian prior on the optical depth, tau = 0.07 +- 0.02
 +
|-
 +
| '''reion''' || A hard prior z_re > 6.5, combined with Gaussian prior z_re = 7 +- 1
 
|-
 
|-
| '''tauprior''' || A Gaussian prior on the optical depth, tau = 0.09 +- 0.013
+
| '''BAO''' || Baryon oscillation data from DR11LOWZ, DR11CMASS, MGS and 6DF
 
|-
 
|-
| '''BAO''' || Baryon oscillation data from DR7, DR9 and and 6DF
+
| '''JLA''' ||   Supernova data from the SDSS-II/SNLS3 Joint Light-curve Analysis
 
|-
 
|-
| '''SNLS''' ||  Supernova data from the Supernova Legacy Survey
+
| '''H070p6''' ||  Hubble parameter constraint, H_0 = 70.6 +- 3.3
 
|-
 
|-
| '''Union2''' ||  Supernova data from the Union compilation
+
| '''theta''' ||  theta_MC fixed to 1.0408
 
|-
 
|-
| '''HST''' || Hubble parameter constraint from HST (Riess et al)
+
| '''WLonlyHeymans''' || Conservative cut of the CFHTLenS weak lensing data + priors
 
|-
 
|-
 
| '''WMAP''' || The full WMAP (temperature and polarization) 9 year data  
 
| '''WMAP''' || The full WMAP (temperature and polarization) 9 year data  
 
|}
 
|}
  
Tags used to identify the model paramters that are varied are described in [[File:parameter_tag_definitions.pdf]]
+
The high-L Planck likelihoods have TT, TE, EE variants from each spectrum alone, plus the TTTEEE joint constraint.
  
== Parameter Chains ==
 
  
We provide the full chains and getdist outputs for our parameter results. The entire grid of results is available from the PLA (link below) as a 2.8GB compressed file. You can also download key chains for the baseline LCDM model here:
+
Tags used to identify the model parameters that are varied are described in [[Media:parameter_tag_definitions_2015.pdf]].  
  
{| class="wikitable"  align="center" style="text-align:left" border="1" cellpadding="5" cellspacing="0"
+
== Parameter Chains ==
|+
 
! Baseline LCDM model chains
 
|-
 
| {{PLASingleFile|fileType=cosmo|name=COM_CosmoParams_base_planck_lowl_post_lensing_R1.10.tar.gz|link=Planck+lensing}}
 
|-
 
| {{PLASingleFile|fileType=cosmo|name=COM_CosmoParams_base_planck_lowl_lowLike_R1.10.tar.gz|link=Planck+WP}}
 
|-
 
| {{PLASingleFile|fileType=cosmo|name=COM_CosmoParams_base_planck_lowl_lowLike_post_lensing_R1.10.tar.gz|link=Planck+WP+lensing}}
 
|-
 
| {{PLASingleFile|fileType=cosmo|name=COM_CosmoParams_base_planck_lowl_lowLike_highL_R1.10.tar.gz|link=Planck+WP+highL}}
 
|-
 
| {{PLASingleFile|fileType=cosmo|name=COM_CosmoParams_base_planck_lowl_lowLike_highL_post_lensing_R1.10.tar.gz|link=Planck+WP+highL+lensing}}
 
|}
 
  
 +
We provide the full chains and getdist outputs for our parameter results. The entire grid of results is available from as a 3.7GB compressed file:
 +
<!--- * {{PLASingleFile|fileType=cosmo|name= COM_CosmoParams_R2.00.tar.gz|link=Full Grid Download}}  ---->
 +
* ''COM_CosmoParams_R2.nn.tar.gz''
 +
Where ''nn'' is the most recent update. You can also download the Bicep2/Keck/Planck (BKP) joint constraints for +r models, and smaller files containing key results in the base model only: 
 +
<!---* {{PLASingleFile|fileType=cosmo|name=COM_CosmoParams_base_plikHM_TT_lowTEB_R2.00.tar.gz|link=Baseline LCDM chains with plikHM_TT_lowTEB}}
 +
* {{PLASingleFile|fileType=cosmo|name=COM_CosmoParams_base_plikHM_TT_lowTEB_R2.00.tar.gz|link=Baseline LCDM chains with all plikHM combinations}}
 +
* {{PLASingleFile|fileType=cosmo|name=COM_CosmoParams_base_lensonly_R2.00.tar.gz|link=CMB lensing only in LCDM}}  --->
 +
* ''COM_CosmoParams_base_plikHM_TT_lowTEB_R2.nn.tar.gz''
 +
* ''COM_CosmoParams_base_plikHM_R2.nn.tar.gz''
 +
* ''COM_CosmoParams_base_lensonly_R2.nn.tar.gz''
 +
* ''COM_CosmoParams_base_r_plikHM_BKP_R2.nn.tar.gz''
  
 
The download contains a hierarchy of directories, with each separate chain in a separate directory. The structure for the directories is
 
The download contains a hierarchy of directories, with each separate chain in a separate directory. The structure for the directories is
  
base_AAA_BBB/XXX_YYY_.../
+
: '' base_AAA_BBB/XXX_YYY_.../''
  
where AAA and BBB are any additional parameters that are variend in addition to the six parameters of the baseline model. XXX, YYY, etc encode the data combinations used. These follow the naming conventions described above under Parameter Tabls.
+
where AAA and BBB are any additional parameters that are varied in addition to the six parameters of the baseline model. XXX, YYY, etc encode the data combinations used. These follow the naming conventions described above under Parameter Tables. Each directory contains the main chains, 4-8 text files with one chain in each, and various other files all with names of the form
  
Each directory contains the main chains, 4-8 text files with one chain in each, and various other files all with names of the form.
+
: ''base_AAA_BBB_XXX_YYY.ext''
  
base_AAA_BBB_XXX_YYY.ext
+
where ''ext'' describes the type of file, and the possible values or ''ext'' are
  
where ext describes the type of file
 
  
{| class="wikitable"  align="center" style="text-align:left" border="1" cellpadding="5" cellspacing="0"  
+
{| class="wikitable"  align="center" style="text-align:left" border="1" cellpadding="3" cellspacing="0" width=800px
 
|+  
 
|+  
! Tag|| Data
+
|- bgcolor="ffdead"       
 +
! Extension || Data
 
|-
 
|-
 
| '''.txt''' || parameter chain file with burn in removed
 
| '''.txt''' || parameter chain file with burn in removed
 
|-
 
|-
 
| '''.paramnames''' || File that describes the parameters included in the chains
 
| '''.paramnames''' || File that describes the parameters included in the chains
 +
|-
 +
| '''.inputparams''' || Input parameters used when generating the chain
 
|-
 
|-
 
| '''.minimum''' || Best-fit parameter values, -log likelihoods and chi-square
 
| '''.minimum''' || Best-fit parameter values, -log likelihoods and chi-square
 
|-
 
|-
| '''.bestfit_cl''' || The best-fit temperature and polarization power spectra and lensing potential (see below)
+
| '''.minimum.theory_cl''' || The best-fit temperature and polarization power spectra and lensing potential (see below)
 
|-
 
|-
| '''.inputparams''' || Input parameters used when generating the chain
+
| '''.minimum.plik_foregrounds''' || The best-fit foreground model (additive component) for each data power spectrum used
 
|-
 
|-
 
| '''.minimum.inputparams''' ||  Input parameters used when generating the best fit
 
| '''.minimum.inputparams''' ||  Input parameters used when generating the best fit
Line 111: Line 136:
 
|}
 
|}
  
In addition each directory contains any importances sampled outputs with additional data. These have names of the form
 
  
base_AAA_BBB_XXX_YYY_post_ZZZ.ext
+
In addition each directory contains any importance sampled outputs with additional data. These have names of the form
  
where ZZZ is the data likelihood that is added by importance sampling.
+
: ''base_AAA_BBB_XXX_YYY_post_ZZZ.ext''
  
In addition to the main ouputs, each directory contains a ''dist'' subdirectory, containing results of chain analysis. File names follow the above convntions, with the following extensions
+
where ZZZ is the data likelihood that is added by importance sampling. Finally, each directory contains a ''dist'' subdirectory, containing results of chain analysis. File names follow the above conventions, with the following extensions
  
{| class="wikitable"  align="center" style="text-align:left" border="1" cellpadding="5" cellspacing="0"  
+
 
 +
{| class="wikitable"  align="center" style="text-align:left" border="1" cellpadding="3" cellspacing="0" width=800px
 
|+  
 
|+  
! Tag|| Data
+
|- bgcolor="ffdead"
 +
! Extension || Data
 
|-
 
|-
 
| '''.margestats''' || mean, variance and 68, 95 and 99% limits for each parameter (see below)
 
| '''.margestats''' || mean, variance and 68, 95 and 99% limits for each parameter (see below)
Line 128: Line 154:
 
|-
 
|-
 
| '''.covmat''' || Covariance matrix for the MCMC parameters
 
| '''.covmat''' || Covariance matrix for the MCMC parameters
|-
 
| '''.corr''' || Correlation matrix for the parameters
 
 
|-
 
|-
 
| '''.converge''' ||  A summary of various convergence diagnostics
 
| '''.converge''' ||  A summary of various convergence diagnostics
 
|}
 
|}
 +
 +
 +
Python scripts for reading in chains and calculating new derived parameter constraints are available as part of CosmoMC, see the readme for details [http://cosmologist.info/cosmomc/readme_planck.html]. The config directory in the download includes information about the grid configuration used by the plotting and grid scripts.
  
 
== File formats ==
 
== File formats ==
  
The file formats are standard March 2013 CosmoMC outputs. CosmoMC includes python scripts for generating tables, 1D, 2D and 3D plots using the provided data. The formats are summarised here:
+
The file formats are standard Jan 2015 CosmoMC outputs. CosmoMC includes python scripts for generating tables, 1D, 2D and 3D plots using the provided data, as well as a GUI for conveniently making plots from grid downloads. The formats are summarised here:
  
 
; Chain files
 
; Chain files
 
: Each chain file is ASCII and contains one sample on each line. Each line is of the format
 
: Each chain file is ASCII and contains one sample on each line. Each line is of the format
  
  weight like param1 param2 param3 ...
+
: '' weight like param1 param2 param3 …''
  
Here ''weight'' is the importance weight or multiplicity count, and ''like'' is the total -log Likelihood. ''param1'',''param2'', etc are the parameter values for the sample, where the numbering is defined by the position in the accompanying.paramnames files.
+
: Here ''weight'' is the importance weight or multiplicity count, and ''like'' is the total -log Likelihood. ''param1'',''param2'', etc are the parameter values for the sample, where the numbering is defined by the position in the accompanying .paramnames files.
  
Note that burn in has been removed from the cosmomc outputs, so full chains provided can be used for analysis. Importance sampled results (wth ''_post'') in the name have been thinnen by a factor of 10 compared to the original chains, so the files are smaller, but this does not significantly affect the effective number of samples. Note that due to the way MCMC works, the samples in the chain outputs are not indpendent, but it is safe to use all the samples for estimating posterior averages.
+
: Note that burn in has been removed from the cosmomc outputs, so full chains provided can be used for analysis. Importance sampled results (with ''_post'') in the name have been thinned by a factor of 10 compared to the original chains, so the files are smaller, but this does not significantly affect the effective number of samples. Note that due to the way MCMC works, the samples in the chain outputs are not independent, but it is safe to use all the samples for estimating posterior averages.
  
 
;.margestats files
 
;.margestats files
 
: Each row contains the marginalized constraint on individual parameters. The format is fairly self explanatory given the text description in the file, with each line of the form
 
: Each row contains the marginalized constraint on individual parameters. The format is fairly self explanatory given the text description in the file, with each line of the form
  
  parameter mean sddev lower1 upper1 limit1 lower2 upper2 limit2 lower3 upper3 limit3
+
: '' parameter mean sddev lower1 upper1 limit1 lower2 upper2 limit2 lower3 upper3 limit3''
  
where sddev is the standard deviation, and the limits are 1: 68%, 2: 95%, 3: 99%. The limit tags specify whether a given limit is one tail, two tail or none (if no constaint within the assumed prior boundary).  
+
: where sddev is the standard deviation, and the limits are 1: 68%, 2: 95%, 3: 99%. The limit tags specify whether a given limit is one tail, two tail or none (if no constraint within the assumed prior boundary).  
  
;.bestfit_cl files
+
;.minimum.theory_cl files
: The contain the best-fit theoretical power spectra (without foregrounds) for each model. The columns are
+
: They contain the best-fit theoretical power spectra (without foregrounds) for each model. The columns are:  <math>l</math>, <math>D^{TT}_l</math>, <math>D^{TE}_l</math>, <math>D^{EE}_l</math>, <math>D^{BB}_l</math>, and <math>D^{dd}_l</math>, were <math>D_l \equiv l(l+1) C_l / (2\pi)</math> in <math>\mu{\rm K}^2</math>. Also <math>D^{dd}_l= [l(l+1)]^2 C^{\phi\phi}_l/(2\pi)</math> is the power spectrum of the lensing deflection angle, where <math>C^{\phi\phi}_l</math> is the lensing potential power spectrum. Note that the lensing spectrum may not be accurate at L > 400 due to the maximum wavenumber and non-linear correction accuracy settings.
  
  l D^TT_l D^TE_l D^EE_l D^BB_l C^dd_l
 
  
The D_l's are all l(l+1) C_l / (2pi)'s in (microK)^2.
+
== References ==
  
C^dd_l= (l(l+1))^2*C^Phi_l/(2pi) is the power spectrum of the lensing deflection angle, where C^Phi_l is the lensing potential power spectrum. For results not including the lensing likelihood, this is the prediction from linear theory; for lensing outputs this includes corrections due to non-linear structure growth. The D_l are output to high L, but not actually computed above Lmax=2500 (Planck), Lmax=4500 (Planck+highL) or Lmax=1500 (WMAP), and L values above these are fixed to a scaled fiducial template.
 
  
 
+
<References />
== References ==
 
  
  
<biblio force=false>
 
#[[References]]
 
</biblio>
 
  
  
  
 
[[Category:Mission products|009]]
 
[[Category:Mission products|009]]

Latest revision as of 11:38, 15 April 2015

Description[edit]

The 2015 cosmological parameter results explore a variety of cosmological models with combinations of Planck and other data. We provide results from MCMC exploration chains, as well as best fits, and sets of parameter tables. Definitions, conventions and reference are contained in Planck-2013-XVI[1]Planck-2015-A15[2].

Production process[edit]

Parameter chains are produced using CosmoMC, a sampling package available here. This includes the sample analysis package (and GUI) GetDist, and the scripts for managing, analysing, and plotting results from the full grid or runs. Chain products provided here have had burn in removed. Some results with additional data are produced by importance sampling.

Note that the baseline model includes one massive neutrino (0.06eV). Grid outputs include WMAP 9 results for consistent assumptions.

Caveats and known issues[edit]

  1. Confidence intervals are derived from the MCMC samples, and assume the input likelihoods are exactly correct, so there is no quantification for systematic errors other than via the covariance, foreground and beam error models assumed in the likelihood codes.
  2. Non-linear lensing modelling uses Halofit; for some extended models and CMB lensing only analyses, tails of the chains may be away from the domain of validity.
  3. The CAMB version used for most results is Dec 2014; the Jan 2015 version is used for lensing-only models with neutrinos, and only differs in the neutrino corrections to the Halofit model.
  4. There is evidence of temperature-polarization leakage that may affect results including high-L polarization; hence use caution in the interpretation of results including polarization
  5. Alternative CamSpec likelihood results in the tables are generated using a slightly older CosmoMC version, with fewer derived parameters and a slightly different BBN predictions for the helium abundance.

Related products[edit]

Results of the baseline parameter exploration runs should be reproducible using CosmoMC with the Planck 2015 likelihood codes (when available).

Parameter Tables[edit]

These list parameter constraints for each considered model and data combination separately. For the baseline likelihood see

There are also larger files including alternative CamSpec and DetSet likelihood results, along with shifts in parameters compared to baseline in units of the baseline error:


Data combination tags used to label results are as follows (see Planck-2013-XVI[1] for full description and references):


Tag Data
plikHM baseline high-L Planck power spectra (plik cross half-mission, 30 <= l <= 2508)
plikDS high-L Planck power spectra (plik cross detsets, 30 <= l <= 2508)
CamSpecHM high-L Planck power spectra (CamSpec cross half-mission, 30 <= l <= 2500)
CamSpecDS high-L Planck power spectra (CamSpec cross detsets, 30 <= l <= 2500)
lowl low-L: Planck temperature only (2 <= l <= 29)
lowTEB low-L temperature and LFI polarization (2 <= l <= 29)
lowEB low-L LFI polarization only (2 <= l <= 29)
WMAPTEB low-L temperature, and LFI+WMAP polarization (2 <= l <= 29)
lensing Planck lensing power spectrum reconstruction
lensingonly Planck lensing power spectrum reconstruction only; T,E fixed to best-fit spectrum + priors
BKP The Bicep-Keck-Planck fiducial B mode likelihood
zre6p5 A hard prior z_re > 6.5
tau07 A Gaussian prior on the optical depth, tau = 0.07 +- 0.02
reion A hard prior z_re > 6.5, combined with Gaussian prior z_re = 7 +- 1
BAO Baryon oscillation data from DR11LOWZ, DR11CMASS, MGS and 6DF
JLA Supernova data from the SDSS-II/SNLS3 Joint Light-curve Analysis
H070p6 Hubble parameter constraint, H_0 = 70.6 +- 3.3
theta theta_MC fixed to 1.0408
WLonlyHeymans Conservative cut of the CFHTLenS weak lensing data + priors
WMAP The full WMAP (temperature and polarization) 9 year data

The high-L Planck likelihoods have TT, TE, EE variants from each spectrum alone, plus the TTTEEE joint constraint.


Tags used to identify the model parameters that are varied are described in Media:parameter_tag_definitions_2015.pdf.

Parameter Chains[edit]

We provide the full chains and getdist outputs for our parameter results. The entire grid of results is available from as a 3.7GB compressed file:

  • COM_CosmoParams_R2.nn.tar.gz

Where nn is the most recent update. You can also download the Bicep2/Keck/Planck (BKP) joint constraints for +r models, and smaller files containing key results in the base model only:

  • COM_CosmoParams_base_plikHM_TT_lowTEB_R2.nn.tar.gz
  • COM_CosmoParams_base_plikHM_R2.nn.tar.gz
  • COM_CosmoParams_base_lensonly_R2.nn.tar.gz
  • COM_CosmoParams_base_r_plikHM_BKP_R2.nn.tar.gz

The download contains a hierarchy of directories, with each separate chain in a separate directory. The structure for the directories is

base_AAA_BBB/XXX_YYY_.../

where AAA and BBB are any additional parameters that are varied in addition to the six parameters of the baseline model. XXX, YYY, etc encode the data combinations used. These follow the naming conventions described above under Parameter Tables. Each directory contains the main chains, 4-8 text files with one chain in each, and various other files all with names of the form

base_AAA_BBB_XXX_YYY.ext

where ext describes the type of file, and the possible values or ext are


Extension Data
.txt parameter chain file with burn in removed
.paramnames File that describes the parameters included in the chains
.inputparams Input parameters used when generating the chain
.minimum Best-fit parameter values, -log likelihoods and chi-square
.minimum.theory_cl The best-fit temperature and polarization power spectra and lensing potential (see below)
.minimum.plik_foregrounds The best-fit foreground model (additive component) for each data power spectrum used
.minimum.inputparams Input parameters used when generating the best fit
.ranges prior ranges assumed for each parameter


In addition each directory contains any importance sampled outputs with additional data. These have names of the form

base_AAA_BBB_XXX_YYY_post_ZZZ.ext

where ZZZ is the data likelihood that is added by importance sampling. Finally, each directory contains a dist subdirectory, containing results of chain analysis. File names follow the above conventions, with the following extensions


Extension Data
.margestats mean, variance and 68, 95 and 99% limits for each parameter (see below)
.likestats parameters of best-fitting sample in the chain (generally different from the .minmum global best-fit)
.covmat Covariance matrix for the MCMC parameters
.converge A summary of various convergence diagnostics


Python scripts for reading in chains and calculating new derived parameter constraints are available as part of CosmoMC, see the readme for details [1]. The config directory in the download includes information about the grid configuration used by the plotting and grid scripts.

File formats[edit]

The file formats are standard Jan 2015 CosmoMC outputs. CosmoMC includes python scripts for generating tables, 1D, 2D and 3D plots using the provided data, as well as a GUI for conveniently making plots from grid downloads. The formats are summarised here:

Chain files
Each chain file is ASCII and contains one sample on each line. Each line is of the format
weight like param1 param2 param3 …
Here weight is the importance weight or multiplicity count, and like is the total -log Likelihood. param1,param2, etc are the parameter values for the sample, where the numbering is defined by the position in the accompanying .paramnames files.
Note that burn in has been removed from the cosmomc outputs, so full chains provided can be used for analysis. Importance sampled results (with _post) in the name have been thinned by a factor of 10 compared to the original chains, so the files are smaller, but this does not significantly affect the effective number of samples. Note that due to the way MCMC works, the samples in the chain outputs are not independent, but it is safe to use all the samples for estimating posterior averages.
.margestats files
Each row contains the marginalized constraint on individual parameters. The format is fairly self explanatory given the text description in the file, with each line of the form
parameter mean sddev lower1 upper1 limit1 lower2 upper2 limit2 lower3 upper3 limit3
where sddev is the standard deviation, and the limits are 1: 68%, 2: 95%, 3: 99%. The limit tags specify whether a given limit is one tail, two tail or none (if no constraint within the assumed prior boundary).
.minimum.theory_cl files
They contain the best-fit theoretical power spectra (without foregrounds) for each model. The columns are: [math]l[/math], [math]D^{TT}_l[/math], [math]D^{TE}_l[/math], [math]D^{EE}_l[/math], [math]D^{BB}_l[/math], and [math]D^{dd}_l[/math], were [math]D_l \equiv l(l+1) C_l / (2\pi)[/math] in [math]\mu{\rm K}^2[/math]. Also [math]D^{dd}_l= [l(l+1)]^2 C^{\phi\phi}_l/(2\pi)[/math] is the power spectrum of the lensing deflection angle, where [math]C^{\phi\phi}_l[/math] is the lensing potential power spectrum. Note that the lensing spectrum may not be accurate at L > 400 due to the maximum wavenumber and non-linear correction accuracy settings.


References[edit]

  1. 1.01.1 Planck 2013 results. XVI. Cosmological parameters, Planck Collaboration, 2014, A&A, 571, A16
  2. Planck 2015 results. XIII. Cosmological parameters, Planck Collaboration, 2016, A&A, 594, A13.

Cosmic Microwave background

(Planck) Low Frequency Instrument