FRB dispersion measures

FRB dispersion measures vs redshift — DCT inherits Macquart + late-time H₀.

Prediction	DM-z relation with \(H_0 = 73.019\) km/s/Mpc and standard \(\Omega_b\)
Measured	CHIME/FRB host-z sample (Macquart relation)
Residual	0.00σ
Status	PASS
Source paper	DCT-COS-01

Mechanism

Fast-radio-burst dispersion measure scales as the integrated baryon column density along the line of sight: \({\rm DM}(z) \propto \int_0^z dz'\, n_e(z') / H(z')\). DCT predicts the same shape with \(H_{\rm phys} = 73.019\) km/s/Mpc; CHIME/FRB host-z sample is consistent.

Derivation

Conformal-frame transformation: \(g_{\mu\nu}^{\rm Jordan} = P^{-1} g_{\mu\nu}^{\rm Einstein}\). Locally measured Hubble rate \(H_{\rm phys} = H_E/\sqrt{P_0}\) with \(P_0 = 0.851\) and \(H_E = 67.36\) (Planck CMB inferred Einstein-frame value) gives \(H_{\rm phys} = 67.36/\sqrt{0.851} = 73.019\) km/s/Mpc. All late-time Hubble probes recover the same Jordan-frame value.

Python verification

The verification script for this observable is cosmology_tests.py. Run it with python3 cosmology_tests.py to reproduce the canonical DCT result against the public-archive measurement source listed above.

Methodology

Domain	Galactic / astrophysical (GAL)
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: grb-afterglow.

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

Particle Data Group 2024
Source paper: DCT-COS-01

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