jla module

Supernova likelihood for SDSS-II/SNLS3

Name: jla

File: cosmosis-standard-library/supernovae/jla_likelihood_v6/jla.so

Version: 6

Author(s):

Marc Betoule

URL: http://supernovae.in2p3.fr/sdss_snls_jla/ReadMe.html

Cite:

http://arxiv.org/abs/1401.4064

Rules:

Assumptions:

SALT2 used to fit light curves
Akima interpolation between mu(z) samples

Explanation

This JLA code uses 731 supernovae from the JLA SDSS-II/SNLS3 sample
to get a likelihood of a given theory mu(z).

Systematic error propagation is done with a collection of separate
covariance matrices for the various light-curve parameters.

You can copy the standard parameters to use for this from demos/demo5.ini

This version (6) includes a simplified form of the likelihood with only one (instead of three) nuisance parameters.
We have not yet exposed this likelihood in cosmosis. The likelihood values of the original
JLA likelihood remain unchanged - there is no need to re-run any old chains with v6.

##Parameters

These parameters can be set in the module's section in the ini parameter file.
If no default is specified then the parameter is required.

Parameter	Description
data_dir	String; dir for other files. Use cosmosis-standard-library/supernovae/jla_v3/data (unless trying a different data set)
data_file	String; dir for other files. Use jla_lcparams.txt (unless trying a different data set)
scriptmcut	String; dir for other files. Use 10.0
mag_covmat_file	String; dir for other files. Use jla_v0_covmatrix.dat
stretch_covmat_file	String; dir for other files. Use jla_va_covmatrix.dat
colour_covmat_file	String; dir for other files. Use jla_vb_covmatrix.dat
mag_stretch_covmat_file	String; dir for other files. Use jla_v0a_covmatrix.dat
mag_colour_covmat_file	String; dir for other files. Use jla_v0b_covmatrix.dat
stretch_colour_covmat_file	String; dir for other files. Use jla_vab_covmatrix.dat

##Inputs

These parameters and data are inputs to the module, either supplied as parameters by the sampler or computed by some previous module. They are loaded from the data block.

Section	Parameter	Description
distances	z	Real vector; redshift sample values for theory
	mu	Real vector; theory distance modulus at sample redshifts
supernova_params	alpha	Real; SN shape parameter coefficient
	beta	Real; SN color parameter coefficient
	M	Real; SN magnitude parameter baseline value; leave this fixed and vary deltaM.
	deltaM	Real; SN magnitude parameter where M_actual = M + deltaM

##Outputs

These parameters and data are computed as outputs from the module

Section	Parameter	Description
likelihoods	JLA_LIKE	Gaussian likelihood for this data set and theory mu(z)

Wiki

cosmosis / default_modules / jla_6

jla module

Supernova likelihood for SDSS-II/SNLS3