pantheon_plus

Likelihood of the Pantheon+ supernova analysis optionally combined with the SH0ES H0 measurement

File

likelihood/pantheon_plus/pantheon_plus_shoes.py

Attribution

Dillon Brout

URL

https://pantheonplussh0es.github.io/

Citations

ApJ 938 110 (2022)

Adam G. Riess et al 2022 ApJL 934 L7

Supernova IA can be used as standardisable candles, letting us estimate a redshift-distance relation. The Pantheon+ sample collected together 1701 light curves of 1550 distinct Type Ia supernovae This module uses that data set to constrain the distance modulus vs redshift relation. This version can optionally also include SH0ES HST measurements of H0 from Cepheid variables over 40 years of data.

Assumptions

  • Pantheon+ statistical and systematic analysis

Setup Parameters

Name

Type

Default

Description

include_shoes

bool

Whether to include SH0ES H0 measurements. Note that the parameter name has an o not a zero.

data_file

str

module_dir/Pantheon+SH0ES.dat

Optional. File containing supernova measurements

covmat_file

str

Pantheon+SH0ES_STAT+SYS.cov_compressed.gz

Optional. File containing supernova measurements

x_name

str

z

Datablock name for input theory redshift

y_section

str

distances

Datablock section for input theory distance modulus

y_name

str

mu

Datablock name for input theory distance modulus

like_name

str

pantheon

Named for the saved output likelihood

likelihood_only

bool

False

Skip saving everything except the likelihood. This prevents you from using e.g. the Fisher matrix sampler but can be faster for quick likelihoods

include_norm

bool

False

Include the normalizing constant at the start of the likelihood. May be needed when comparing models.

Input values

Section

Name

Type

Default

Description

distances

z

real 1d

Redshifts z of calculated theory D_A(z)

D_A

real 1d

Angular diameter distance D_A(z)

supernova_params

M

real

SN IA absolute magnitude

Output values

Output values

Section

Name

Type

Description

likelihoods

pantheon_like

real

Gaussian likelihood value of supplied theory mu(z) and M

data_vector

pantheon_covariance

real 2d

Fixed covariance matrix, only if likelihood_only=F

pantheon_data

real 1d

Fixed data vector mu_obs, only if likelihood_only=F

pantheon_simulation

real 1d

Simulated data vector including simulated noise for e.g. ABC, only if likelihood_only=F

pantheon_theory

real 1d

Predicted theory values mu_theory(z_obs) only if likelihood_only=F

pantheon_chi2

real

chi^2 value, only if likelihood_only=F