CosmoFit.TauLikelihood

class CosmoFit.TauLikelihood(cosmology, version='planck2018')[source]

Bases: GaussianPriorLikelihood

The Planck 2018 large-scale-polarization constraint on the reionization optical depth, tau = 0.0544 +- 0.0073.

Only meaningful alongside PlanckLiteLikelihood, which covers l >= 30 only. There, tau enters solely through the exp(-2 tau) damping of the spectra and is therefore degenerate with the primordial amplitude A_s; this prior is what breaks that degeneracy, and it is the standard companion to a high-l-only CMB fit rather than an optional extra. Without it, sigma8 and anything derived from it are unconstrained.

Parameters:

version (str)

__init__(cosmology, version='planck2018')[source]
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