Determine whether the non-SDSS transverse BAO offset is method-wide or coincidental

Determine whether the residual transverse BAO calibration offset measured in the four non-SDSS measurements is common to the angular BAO analysis method or is merely coincidental.

Background

The paper compares transverse BAO measurements from two SDSS-based compilations and from a separate non-SDSS set. The non-SDSS measurements yield a calibration factor of ε = 1.046 ± 0.020, which lies between the two SDSS determinations and is 2.5 standard deviations above unity.

Because the non-SDSS measurements use different templates, the template correction applied to the Menote–Marra compilation cannot be directly transferred to them. The authors note that only four measurements are available, leaving unresolved whether the residual offset reflects a systematic common to the angular BAO method or a statistical coincidence.

References

These measurements use different templates, so the MM correction does not apply to them; if a template bias of this kind were the only systematic affecting angular BAO, they should still return ε= 1. That they sit $2.5\sigma$ above unity suggests a residual offset, though four measurements cannot establish whether it is common to the method or coincidental.

— A blind spot in transverse BAO calibration  (2608.20296 - Sapone, 20 Aug 2026) in Section “Redshift dependence”