In Pantheon+ and Union3, with Ωm = 0.315 ± 0.007, does the preference for dynamical dark energy persist after excluding each of the seven DESI DR2 BAO bins?
Public summary of an internal test, not yet independently validated or published.
Question investigated
In Pantheon+ and Union3, with Ωm = 0.315 ± 0.007, does the preference for dynamical dark energy persist after excluding each of the seven DESI DR2 BAO bins?
Test conditions
Repeat the fits to Pantheon+ and Union3, excluding one DESI DR2 BAO bin at a time: z = (0.295); (0.51); (0.706); (0.934); (1.321); (1.484); (2.33). Retain the other data, covariances, assumptions and comparison criteria. Adopt Ωm = 0.315 ± 0.007. Measure changes in fit quality and in the direction of the dark-energy parameters.
Result
The preference for dynamical dark energy retained the same direction in every tested group exclusion. This stability is limited to the analyzed data, priors and groupings; it does not establish a globally significant detection.
Physical interpretation
This test assesses the influence of each BAO bin on the conclusion obtained with the same supernova data and cosmological assumptions. The exclusions add no independent observations.