Observable detail · COSMOLOGY

Spectral index n_s

Prediction1 − 4/120 = 0.9667
Measured0.9649 (Planck)
Residual0.4σ
Statushit
Source paperDCT-CMB-01

Mechanism

n_s = 1 − 4/N_vertex with N_vertex = 120 from the 600-cell. The factor 4 = D_spacetime − 0 spacelike directions on the inflationary slow-roll trajectory.

Derivation

n_s = 1 − 4/N_vertex with N_vertex = 120 from the 600-cell. The factor 4 = D_spacetime − 0 spacelike directions on the inflationary slow-roll trajectory.

The closed-form prediction is

$$ \text{predicted} = 1 − 4/120 = 0.9667 $$

against the measurement 0.9649 (Planck), giving residual 0.4σ.

Python verification

The verification script for this observable is cmb_analysis.py. Run it with python3 cmb_analysis.py to reproduce the canonical DCT result against the public-archive measurement source listed above (Planck 2018 VI.).

Methodology

DomainCosmology (COS)
Input data sourceSee "References" below for the canonical public-archive citation. The verification script consumes the published value (or the public dataset, where applicable) and compares against the DCT closed-form prediction.
Measurement procedureThe measured value used here is the most recent peer-reviewed central value plus 1σ uncertainty from the cited reference; no internal recalibration is applied.
Acceptance thresholdHIT: residual within 1σ of measurement. SOFT: directional agreement, residual within bracketing range. OPEN: untested or unresolved.
Falsification thresholdMISS: prediction excluded at ≥3σ by the canonical measurement under the corpus-canonical (constant-\(P_0\)) treatment.
Current statusSee the verdict pill in the prediction table above.

Cross-references

Related observables in the same domain: planck-cmb-tt · planck-a-l.

Aggregate views: /predictions/ · /scorecard/ · /empirical/ · /outstanding-problems/.

Audit notes

Status post-: this observable's verdict above reflects the corpus-canonical (constant-\(P_0\)) treatment. Any prior interim Avrami-extension framing has been reverted (see /updates/ for the change log). The cluster-paper deep-link above (DCT-CMB-01) is the canonical source of the derivation chain.

References

Back to all observables or the predictions table.