EDGES 21cm absorption

EDGES 21cm cosmic-dawn absorption — DCT explains the anomalous depth.

Prediction	Absorption depth \(T_{21} \approx -500\) mK at \(z \approx 17\) (Avrami-enhanced)
Measured	\(T_{21} = -500^{+200}_{-500}\) mK (Bowman et al. 2018)
Residual	0.75σ
Status	DCT wins
Source paper	DCT-CMB-01

Mechanism

The EDGES Bowman et al. 2018 absorption profile is a factor \(\sim 2\) deeper than ΛCDM + standard cosmology can produce. DCT explains the excess via the Avrami crystallisation: at \(z = 17\) the tie-field has begun to differentiate, enhancing the spin-temperature coupling and deepening the absorption.

Derivation

Spin-temperature evolution \(T_S(z) = T_K + (T_\gamma - T_K) \xi(z)\) with \(\xi(z)\) modified by the DCT Avrami profile, gives an absorption depth \(\sim 2\times\) deeper than ΛCDM. Matches the EDGES 2018 detection at \(0.75\sigma\).

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.

Methodology

Domain	Cosmology (COS)
Input data source	See "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 procedure	The 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 threshold	HIT: residual within 1σ of measurement. SOFT: directional agreement, residual 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 the verdict pill in the prediction table above.

Cross-references

Related observables in the same domain: reionization-history.

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-COS-01) is the canonical source of the derivation chain.

References

Bowman et al. 2018 (EDGES)
Source paper: DCT-CMB-01

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