BAO priors and dark-energy robustness
Individual run · T-1b7542e82bf0
Public summary of an internal test, not yet independently validated or published.
Question investigated
With a BAO scale-parameter prior of 30 ± 2 and Ωm = 0.3 ± 0.01, does the preference for dynamical dark energy in Pantheon+, DES-SN5YR and Union3 persist after excluding each tracer block?
Test conditions
Fit Pantheon+, DES-SN5YR and Union3 with Ωm = 0.3 ± 0.01 and a BAO scale-parameter prior of 30 ± 2. Separately exclude the three BAO blocks at z = (0.295, 0.51, 0.706); (0.934, 1.321, 1.484); (2.33). Compare the response of the fits while varying only the width of the acoustic-ruler calibration prior.
Result
The group exclusions produced unequal responses in the fit. The comparison established neither independence of the preference from every group nor exclusive dependence on any one group.
Physical interpretation
The analysis measures sensitivity to the width of the acoustic-ruler prior in the adopted model. This test provides neither a physical calibration of the ruler nor an independent constraint on the early Universe.