Neutron star radii (NICER)

Neutron-star radii from NICER X-ray pulse profiling — DCT inherits GR + EOS.

Prediction	\(R_{1.4} = 12.4 \pm 0.5\) km (nuclear EOS + TOV)
Measured	NICER J0740 + J0030: \(R_{1.4} = 12.5 \pm 1.0\) km
Residual	0.20σ
Status	PASS
Source paper	DCT-SBD-01

Mechanism

DCT inherits GR strong-field; neutron-star mass-radius and \(M_{\rm max}\) follow from the TOV equation with the standard nuclear equation of state. Tidal Love numbers and post-Keplerian parameters in binary pulsars are unchanged from the GR prediction.

Derivation

Same TOV+EOS argument as for \(M_{\rm max}\). NICER X-ray pulse profiling of J0740 and J0030 gives \(R_{1.4} = 12.5 \pm 1.0\) km, consistent with the DCT-inherited GR+EOS prediction at \(0.20\sigma\).

Python verification

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

Methodology

Domain	Solar-system / strong-gravity (GR)
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: ns-mmax-j0740 · gw170817-tidal.

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

References

PSR J0740+6620 NICER
Source paper: DCT-SBD-01

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