Data & code to reproduce the 3–4 M⊙ gap analysis (MEG ceiling + mask + selection) – v1.0.0

Reproducible data and code for “A Quantized Steepness Ceiling Explains the 3–4 M⊙ Compact‑Remnant Gap.”

This package contains the machine‑readable datasets and notebooks used to generate the results and figures in the paper, "A Quantized Steepness Ceiling as the Origin of the 3-4 Solar Mass Compact-Remnant Gap". It includes (i) the electromagnetic (EM) mass anchors for isolated, long‑lived neutron stars, (ii) the gravitational‑wave (GW) event subset used in the inference, (iii) the selection surface tabulation the detection efficiency grid on the mass–mass plane, with constant‑chirp‑mass contours), (iv) prior configurations, (v) event‑level posterior sample archives, and (vi) notebooks that reproduce the coherence mask, posterior‑predictive checks, and the ceiling calculations.

Contents (top‑level folders)
Data/ – CSVs for the EM anchor sample (PSR J1614‑2230, J0348+0432, J0740+6620, J0952‑0607; medians with 90% CIs) and the GW event list used in the paper; companion README with source citations (NICER/radio for EM; LVK catalogs for GW).Selection/ – Tabulated α(M1,M2)α(M1​,M2​) grid used in Eqs. (26)–(27) of the paper, plus plotting helpers for constant‑chirp‑mass contours.Priors/ – YAML files defining baselines and mask parameters (isolated and binaries).Post/ – HDF5 posterior samples for each EM and GW object referenced in the paper (e.g., post/j0740.h5), matching the analysis tables.Notebooks/ – Runnable notebooks that:derive the Unified Limit (U) and harmonic ladder stride λ (methods note) andreproduce the thin‑shell observational ceiling (GR kinematics) andregenerate Figures/PPC diagnostics.Figures/ – Static assets used in the manuscript (e.g., mask overlays).README.md – End‑to‑end instructions; environment (requirements.txt) and license (text: CC‑BY‑4.0; code: MIT).Methodological cross‑refs
The notebooks implement the two independent routes to the ceiling used in the paper: the ladder route (quantized EDG coherence with stride λ ≃ 2.27) and the thin‑shell route (near‑horizon amplification A shell ≈ 8±25%). See the compact methods note and the longer supplement for derivations and minimal code cells.
For historical context (the Letter variant that first presented the ladder truncation), see the archived preprint.

Provenance
EM masses come from NICER/radio timing (as cited in the paper’s tables); GW events are drawn from LVK catalogs as listed in Data/gw_events.csv. Every figure and statistic in the manuscript can be regenerated from this bundle with the provided notebooks.