CosmoFit.H0Likelihood

class CosmoFit.H0Likelihood(cosmology, version='sh0es2022')

Bases: GaussianPriorLikelihood

A local distance-ladder H0 measurement.

Versions: "sh0es2022" (default; Riess et al. 2022, 73.04 +- 1.04), "sh0es2024" (Breuval et al. 2024, the JWST/HST Cepheid re-calibration, 73.17 +- 0.86), and "tdcosmo2025" (Birrer et al. 2025, strong-lensing time delays, 71.6 +- 3.6 – independent of the Cepheid ladder entirely, and the one to reach for when the question is whether the tension survives dropping SH0ES).

Do not combine two of them: they measure the same number.

Parameters:

version (str)

__init__(cosmology, version='sh0es2022')

Parameters:

version (str)

Methods

__init__(cosmology[, version])
chi2()	Chi-square statistic.
log_likelihood()	Return log-likelihood.
model()	Predicted value of the constrained quantity.
predictions()	Alias for model().
residuals()	Data minus model residual (a length-1 vector).
summary()	Return a summary of the likelihood evaluation.

Attributes

n_data	Number of data points.
name_and_size	Name together with the number of data points.
observable