Observable detail · COS
KiDS-Legacy 2025 \(S_8\)
| Prediction / mechanism | \(S_8 \approx 0.776\) under canonical constant-\(P_0\); KiDS-Legacy 2025 measures \(0.815 \pm 0.022\) (Wright et al. 2025). |
|---|---|
| Measured | KiDS-Legacy 2025: \(S_8 = 0.815 \pm 0.022\) (Wright et al. 2025). |
| Residual / status | \(\sim\!1.8\sigma\) tension under canonical constant-\(P_0\) |
| Status | MISS |
| Source paper | DCT-BAO-01 |
Mechanism
Linearised perturbation kernel on a \(\Lambda\)CDM background suppresses late-time growth by \(\sim\!1\!-\!P_0\). Constant-\(P_0\) gives the \(\sim\!1.8\sigma\) tension; an interim Avrami-extended branch that closed it was reverted on.
Derivation
The derivation chain follows the cluster paper DCT-BAO-01 and reduces to the canonical DCT constants (\(P_0 = 0.851\), \(\omega_0 = 50{,}037\), \(c_{BD} = 138{,}189\), master identity \(2\omega_0 + 3 = c_{BD} \cdot P_0^2 = 100{,}077\)). See the cluster paper for the full multi-line derivation.
Methodology
| Domain | Cosmology (COS) |
|---|---|
| Input data source | See "References" below for the canonical public-archive citation. |
| Measurement procedure | The measured value used here is the most recent peer-reviewed central value plus 1σ uncertainty from the cited reference. |
| Acceptance threshold | HIT: residual within 1σ of measurement. SOFT: directional agreement within bracketing range. OPEN: untested or unresolved. |
| Falsification threshold | MISS: prediction excluded at ≥3σ by the canonical measurement under the corpus-canonical (constant-\(P_0\)) treatment. |
| Current status | See verdict pill above. |
Python verification
Verification script: audit_fails.py. Run with python3 audit_fails.py to reproduce the canonical DCT result against the public-archive measurement source listed below.
Cross-references
Related observables: s-8 · des-y3-cosmic-shear · planck-act-s8 · desi-full-shape.
Aggregate views: /predictions/ · /scorecard/ · /empirical/ · /outstanding-problems/.
Audit notes
This sub-page is part of the post-build-out of the observable archive (see the observable index). Verdict reflects the corpus-canonical (constant-\(P_0\)) treatment. The cluster-paper deep-link above (DCT-BAO-01) is the canonical source of the derivation chain.
References
- Wright et al. 2025 — KiDS-Legacy \(S_8\)
- Source paper: DCT-BAO-01
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