Z3 Pre-Registration: Cross-Survey Ωm Baseline Unification Test (v0.2)

Status: v0. 2 canonical at uha commit 839ce60. Deposit-ready. GATE: OPEN given by Eric 2026-05-04 17: 42 UTC. This deposit pre-registers Track B of the three-track UHA + EB carrier program: the cross-survey Ωm baseline common-baseline audit. Track B asks whether different cosmological surveys use different Ωm derivation chains and baselines, whether those differences create systematic effects appearing as cosmological tensions, and whether applying a unified UHA-derived Ωm baseline reduces those tensions across surveys. Z3 is not a Hubble-tension solution paper. It is a pre-registered cross-survey common-baseline audit. Its success condition is not "H0 solved" — it is "a locked Ωm substitution reduces joint tension under identical likelihoods, without extra degrees of freedom, and robustly across local-calibrator routes. " Z3 does not directly challenge the SH0ES distance-ladder calibration. It tests whether cross-survey Ωm baseline substitution changes the joint-inference tension after the local-ladder H0 measurement is held fixed as a public-data constraint. Hypotheses (Track B): H0-Z3: Surveys use Ωm baselines that agree within statistical uncertainty (|ΔΩₘ| 3) for Track B adjudication; explicit non-challenge of SH0ES distance ladder; clean-null = valid publishable outcome surfaced. Full changelog in §11 of the manuscript. Public-data scope: SH0ES R22, Planck 2018, KiDS-1000, DES Y3, DESI DR1, Pantheon+. Dataset versions, release dates, and access dates recorded at analysis start. Provenance: Source protocol: OmegaMBaselineUnificationExperimentCompleteᵥ1. 0₇7b639c. md (commit 77b639c; patent gates removed 2026-05-01) Companion protocol: UHACoordinateFrameworkExperimentCompleteᵥ1. 0₇7b639c. md Z0 umbrella: DOI 10. 5281/zenodo. 19881689 (deposited 2026-04-29) Z2 audit framework: DOI 10. 5281/zenodo. 19908184 (deposited 2026-04-29) EB carrier theorem: RSOS-260797 r4 (under review) UHA patent: US 63/902, 536 Bootstrap commit: 839ce60 in github. com/abba-01/uha This Z3 deposits the Ωm-baseline-unification hypothesis as one candidate explanation for cross-survey cosmological tensions. Other candidates remain open and are listed in §5.