Dark energy evolves: a CPL (w₀, wₐ) fit to DESI DR2 BAO + CMB + Pantheon+ beats ΛCDM by Δχ² = 6.97 (2.16σ), with w₀ = -0.849 and wₐ = -0.548. CORRECTED 2026-07-26: the earlier Δχ² = 8.2 (2.4σ) used a transposed DESI Lyman-α covariance pairing — see the audit log.
Full likelihood refit of DESI DR2 BAO with compressed CMB priors and Pantheon+ supernovae. The preference for evolving dark energy is real but modest, and it dropped by 0.23σ when we found and fixed a covariance-ordering bug in our own loader. Direction unchanged: w₀ > -1, wₐ < 0.
TENSION — the registry's self-check flags this claim
Declared contradiction with USR-2026-0042 QUARANTINED — “Multi-probe bootstrap w₀ departure from -1 at 6.8σ.”. One of these claims must eventually fall.
Declared contradiction with USR-2026-0043 QUARANTINED — “Multi-probe bootstrap wₐ departure at 7.8σ.”. One of these claims must eventually fall.
automated sweep · exact quantity-name match · flagged when |Δ| > 3σ combined · resolves only by evidence — raw feed
Falsify-box — how to kill this claim
Verification record — every quoted number, re-run 2026-07-26
| quantity | measured | verdict |
|---|---|---|
| w₀ best fit | w₀ = -0.849 | MATCH |
| wₐ best fit | wₐ = -0.548 | MATCH |
| Δχ² ΛCDM → w₀wₐCDM | Δχ² = 6.97 (was 8.2 before the Lyα covariance fix) | MATCH |
| evolving-DE preference | 2.16σ (was 2.4σ before the Lyα covariance fix) | MATCH |
Provenance
script status: PRESENT
datasets: DESI DR2 BAO · Planck CMB (compressed) · Pantheon+ (full cov) · claim-scripts (downloadable from /data — run it yourself)
re-run: 2026-07-26
Edges
Status, honestly
re-run 2026-07-26 after self-found covariance bug; preference survives at reduced significance. Status here is computed from evidence — the author cannot set it, and neither can we. Independent reproduction would move it; nothing else will.
What this claim's own script draws. These are the founder's committed outputs — the same plots the script regenerates on any machine that runs it.
