H2 Acceptance Report
Canonical evidence page: This compatibility path is preserved for older links. The canonical report is now H2 metric reconstruction acceptance.
Issue: sci-dug.3
Date: June 7, 2026
Gate: 02 H2 metric reconstruction from pulse comparisons
Verdict
H2 is accepted at the ideal fixed-event level and partially accepted at the finite-data prototype level.
Accepted:
- ideal fixed-event uniqueness of the Lorentzian metric under the reviewed assumptions
- separation of metric uniqueness from event-manifold identification
- finite pulse-record schema for practical records
- first executable finite-data slices for Minkowski, weak-static, stationary direction timing, Shapiro-style spatial delay, and weak-wave differential arm timing, with the Shapiro and weak-wave slices treated as calibrated response benchmarks rather than full raw-record schema implementations
- finite-data gauge and stability conditions for restricted ansatz fits, with first-slice uncertainty propagation demonstrated in code
- sufficient raw-relational conditions for promoting event graphs to fixed-event inputs
Not accepted:
- general reconstruction of an arbitrary metric from sparse finite records
- automatic raw-relational derivation of the smooth event manifold, clock embeddings, or proof-grade signal directions for arbitrary records
- practical metric reconstruction without a stated ansatz, gauge convention, calibration model, and nuisance model
Artifacts
Proof and schema:
- H2 fixed-event theorem
- H2 finite pulse-record schema
- H2 finite-data stability and gauge conditions
- H2 raw relational identifiability
- Roadmap
Code:
src/pulse_model/h2_reconstruction.py
Executable checks:
tests/test_h2_reconstruction.py
Accepted Ideal Result
The ideal H2 theorem proves the following bounded statement:
Given a fixed smooth event region, incidence map, embedded clock segments, proof-grade signal directions or infinitesimal signal curves, dense null-rich signal data, clock-rich timelike samples, calibrated universal clocks, and a compatible Lorentzian metric, no second compatible Lorentzian metric exists on that fixed-event realization.
The proof strategy is:
- signal directions determine the null cone
- null cones determine the conformal metric class
- calibrated pulse-derived timelike durations fix the conformal factor
- coordinate freedom remains as diffeomorphism gauge
This is enough to make the right ideal H2 target.
The raw-relational appendix states sufficient conditions under which event graphs can supply the fixed-event inputs. It is not a proof that arbitrary raw pulse records automatically produce the event manifold or signal tangent directions.
Accepted Finite Prototype Result
The finite-data work is accepted only as a restricted prototype.
Implemented slices:
| Slice | Accepted result | Gauge or ansatz |
|---|---|---|
| Minkowski static clocks | Equal pulse-derived clock rates recover the flat static-clock slice | Reference-clock time-scale gauge |
| Weak static field | Clock ratios recover potential differences | Reference clock fixes additive potential convention |
| Stationary direction timing | Counter-propagating signal times recover a signed timing asymmetry | Observable asymmetry, not unique coordinate |
| Spatial delay | Shapiro-style benchmark records recover a proxy | Calibrated endpoint geometry and mass model supplied as interpretation metadata |
| Weak wave | Differential arm timing benchmark records recover injected | Fixed arm geometry, polarization basis, and long-wavelength approximation supplied as interpretation metadata |
The prototype demonstrates that selected pulse/signal-style records and calibrated response benchmarks can recover selected metric-response parameters with explicit tolerances and uncertainty propagation. It does not yet reconstruct a general metric field or implement the full finite schema for every slice.
Stability And Gauge Decision
Finite H2 stability is accepted only under the conditions in the stability appendix:
- the metric or response ansatz is stated
- gauge choices are stated
- nuisance variables are fixed, bounded, or jointly estimated
- the residual and covariance model are stated
- the gauge-fixed Jacobian or equivalent sensitivity calculation is full rank for the claimed parameters
- uncertainty propagation is reported
- known degeneracies are named
The current executable prototype satisfies the first-slice gauge conventions and closed-form uncertainty propagation checks. It does not yet satisfy the full Jacobian/covariance stability program for arbitrary finite networks, all nuisance parameters, or full metric-field reconstruction.
Remaining Assumptions
H2 still depends on:
- clock universality after calibration
- signal propagation by the relevant null structure
- correct signal-link labels
- controlled environmental clock shifts
- enough clock and signal richness for the claimed ansatz
- explicit gauge fixing
- correct nuisance modeling
- finite-data sensitivity above numerical and measurement noise floors
- raw-relational event and signal identifiability conditions for claims beyond fixed-event reconstruction
H3 Start Decision
H3 can safely start, with a boundary.
H3 may use the ideal fixed-event H2 result as a metric equivalence-class input:
It may also use the finite prototype outputs as toy or ansatz-level reconstructed metric-response data.
H3 must not assume that H2 has already solved raw-relational event-manifold identification or arbitrary sparse finite-data metric reconstruction. The first H3 task should define a loop observable against a fixed-event or explicitly gauge-fixed reconstructed metric object, then state which parts depend on later H2 strengthening.
Gate Decision
The 02 H2 metric reconstruction from pulse comparisons gate is:
- accepted for the ideal fixed-event uniqueness theorem
- partially accepted for finite-data reconstruction prototypes under stated ansatz and gauge conditions, with full finite-data stability still conditional
- conditional for raw-relational identifiability under the sufficient conditions in the appendix
- not accepted for arbitrary sparse-record metric reconstruction
This is sufficient to unblock the first H3 loop-observable work, provided H3 keeps the fixed-event and gauge boundaries explicit.