DES and DESI BAO Data Anchor Flat ΛCDM Across Redshift Range with Sub-Percent Agreement
DES and DESI measurements demonstrate sub-percent consistency with CMB-derived distances in flat ΛCDM, with low-redshift supernova discrepancies likely due to systematics. Cross-validation across recombination to z~1 reduces room for evolving dark energy explanations of Hubble tension. The work highlights the power of multi-probe anchors over single-survey claims.
The study directly tests distance-redshift relations from CMB acoustic scale at recombination through DESI BAO at z~1 and DES Type Ia supernovae. By imposing the CMB prior, it derives an Ω_m value mildly lower than Planck but within statistical tolerance, with the high-redshift DES sample fitting ΛCDM well. This cross-survey validation strengthens the standard model amid ongoing Hubble tension debates by showing a single parameter set spans from local universe to last scattering. Low-redshift supernova anchors display a 0.05 mag offset absent in preliminary DEBASS data, pointing to calibration issues over new physics. The analysis draws on established BAO scaling from earlier SDSS and BOSS surveys plus Planck 2018 CMB constraints to isolate the tension source. It avoids overinterpreting correlations by focusing on the specific parameter combination that DESI constrains tightly. Future data releases from both surveys can test whether the mild Ω_m offset persists at higher precision.
DESI collaboration: Full Year-3 BAO release within 12 months will tighten the Ω_m constraint below 0.8% and resolve whether the current 1.5σ offset with Planck persists or vanishes.
Sources (3)
- [1]Primary Source(https://arxiv.org/abs/2606.18374)
- [2]Supporting Source(https://arxiv.org/abs/1807.06209)
- [3]Supporting Source(https://arxiv.org/abs/2404.03002)