CosmoFit.SDSSBAOLikelihood¶

class CosmoFit.SDSSBAOLikelihood(cosmology, version='dr12+dr16')[source]¶

Bases: BAODistanceLikelihood

Combined SDSS BAO-only likelihood: BOSS DR12 (z=0.38, 0.51) + eBOSS DR16 LRG (z=0.698) + eBOSS DR16 QSO (z=1.48), each an independent, non-overlapping-redshift measurement – see load_sdss_bao() for why BOSS DR12’s usual third bin (z=0.61) is omitted.

Same (z, value, observable-type) structure as DESILikelihood, so it shares the latter’s model()/residuals()/chi2() implementation via BAODistanceLikelihood.

Warning

Do not combine "desi" and "sdss_bao" in the same Fitter fit – DESI’s own footprint and redshift ranges overlap the BOSS/eBOSS samples this dataset is built from (DESI is, among other things, an SDSS successor survey targeting much of the same sky), so treating them as independent would double-count structure.

References

Alam et al. (2017), arXiv:1607.03155 (BOSS DR12). eBOSS Collaboration / Alam et al. (2021), arXiv:2007.08991 (eBOSS DR16 summary). Data as distributed by CobayaSampler/bao_data (originally with CosmoMC).

__init__(cosmology, version='dr12+dr16')[source]¶

Methods

`__init__`(cosmology[, version])
`chi2`()	Compute the BAO chi-square.
`log_likelihood`()	Return log-likelihood.
`model`()	Compute the theoretical BAO observables.
`predictions`()	Alias for model().
`residuals`()	Compute the BAO residual 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.