# AB_BRIDGE_INDEX.txt
# STELLAR_BOUNDARY_DYNAMICS_I
# A–B Bridge — Pre-Collapse Profiles vs Post-Collapse Light Curves

BRIDGE:
A–B

PARENT DATASET:
stellar_boundary_dynamics

PURPOSE:
Compare the processed Phase A and Phase B structural-vector outputs after both
phases have reached the same normalization-reviewed v2 layer.

This bridge asks whether pre-collapse stellar radial structures and observed
post-collapse supernova light-curve responses occupy compatible, separated, or
transition-linked regions of structural-vector space.

PHASE A:
A_mesa_precollapse_tracks

PHASE A DATA STATUS:
Real processed pre-supernova radial-profile data.
Not scaffold.
Not MESA inlists.
Not full time-resolved history.data tracks.

PHASE A SOURCE:
Zenodo 5556959
Different to the core: the pre-supernova structures of massive single and binary-stripped stars

PHASE A SELECTED FILES:
profile_single_M12.09_128net.data
profile_single_M19.98_128net.data

PHASE A PROCESSING CHAIN:
pre-supernova profile .data
→ A pre-supernova radial profile ladder CSV
→ A STRUC-PERC-I canonical input
→ A numeric STRUC-PERC-I ladder
→ A STRUC-PERC-I batch result
→ A alpha-application grid
→ A first-pass 5D vector
→ A normalization-reviewed v2 vector

PHASE A REQUIRED BRIDGE INPUT:
../A_mesa_precollapse_tracks/alpha_application/normalization_review/A_5D_VECTOR_SUMMARY_v2.csv

PHASE A NORMALIZATION REVIEW STATUS:
Comparable objects: 0
Scale-review-needed objects: 2
High-kappa-attention objects: 1

PHASE A REVIEW NOTE:
Both A objects show composition-channel dominance. This is not a failure, but
A–B comparison must use the reviewed v2 summary rather than raw v1 vectors.

PHASE B:
B_supernova_light_curves

PHASE B DATA STATUS:
Observed supernova light-curve data processed into structural light-curve ladders.
Phase B is post-collapse observable response data.

PHASE B SELECTED OBJECTS:
SN1987A
SN1993J
SN1999em
SN2011dh
SN2012aw
SN2013ej

PHASE B PROCESSING CHAIN:
Open Supernova Catalog / AstroCats JSON
→ B light-curve ladder CSV
→ B STRUC-PERC-I canonical input
→ B numeric STRUC-PERC-I ladder
→ B STRUC-PERC-I batch result
→ B alpha-application grid
→ B first-pass 5D vector
→ B normalization-reviewed v2 vector

PHASE B REQUIRED BRIDGE INPUT:
../B_supernova_light_curves/alpha_application/normalization_review/B_5D_VECTOR_SUMMARY_v2.csv

PHASE B NORMALIZATION REVIEW STATUS:
Comparable objects: 1
Scale-review-needed objects: 5
High-tail/kappa-attention objects: 1

PHASE B REVIEW NOTE:
B vectors are usable only through the reviewed v2 summary. SN2012aw remains the
main high-tail/high-kappa special case.

BRIDGE INPUTS:
inputs/A_5D_VECTOR_SUMMARY_v2.csv
inputs/B_5D_VECTOR_SUMMARY_v2.csv

RECOMMENDED LOCAL INPUT COPIES:
Copy:

A_mesa_precollapse_tracks/alpha_application/normalization_review/A_5D_VECTOR_SUMMARY_v2.csv

to:

AB_bridge/inputs/A_5D_VECTOR_SUMMARY_v2.csv

Copy:

B_supernova_light_curves/alpha_application/normalization_review/B_5D_VECTOR_SUMMARY_v2.csv

to:

AB_bridge/inputs/B_5D_VECTOR_SUMMARY_v2.csv

BRIDGE OUTPUT STRUCTURE:
AB_bridge/
  AB_BRIDGE_INDEX.txt

  inputs/
    A_5D_VECTOR_SUMMARY_v2.csv
    B_5D_VECTOR_SUMMARY_v2.csv

  comparisons/
    AB_VECTOR_PAIRWISE_COMPARISON.csv
    AB_DOMAIN_CENTROID_COMPARISON.csv
    AB_OBJECT_RANKING.csv

  summaries/
    AB_BRIDGE_SUMMARY.csv
    AB_BRIDGE_INTERPRETATION.txt

NEXT SCRIPT:
tools/ab_bridge_compare.py

SCRIPT INPUTS:
AB_bridge/inputs/A_5D_VECTOR_SUMMARY_v2.csv
AB_bridge/inputs/B_5D_VECTOR_SUMMARY_v2.csv

SCRIPT OUTPUTS:
AB_bridge/comparisons/AB_VECTOR_PAIRWISE_COMPARISON.csv
AB_bridge/comparisons/AB_DOMAIN_CENTROID_COMPARISON.csv
AB_bridge/comparisons/AB_OBJECT_RANKING.csv
AB_bridge/summaries/AB_BRIDGE_SUMMARY.csv
AB_bridge/summaries/AB_BRIDGE_INTERPRETATION.txt

COMPARISON FEATURES:
mean_GR
var_GR
anisotropic_persistence_bounded
admissibility_persistence
collapse_onset_radius
kappa_connect_reference
tail_dominance_reference

FEATURE USE NOTES:

mean_GR:
Compares average deformation response scale.

var_GR:
Compares deformation response variability.

anisotropic_persistence_bounded:
Uses bounded v2 anisotropy to prevent raw scale domination.

admissibility_persistence:
Compares fraction of alpha-grid states that remain valid.

collapse_onset_radius:
Compares deformation radius before instability appears. If collapse_observed=no
in a phase, this records the maximum tested radius.

kappa_connect_reference:
Carries STRUC-PERC-I connectivity scale into the bridge.

tail_dominance_reference:
Carries STRUC-PERC-I tail dominance into the bridge.

COMPARISON METHODS:
1. Pairwise A–B vector distance
   Compare every A object against every B object.

2. Domain centroid comparison
   Compute A-domain centroid and B-domain centroid in normalized v2 feature space.

3. Object ranking
   Rank which B light-curve responses lie closest to the A pre-collapse profile
   region under the current vector representation.

4. Separation score
   Estimate whether A and B are strongly separated, weakly separated, or
   partially overlapping in reviewed structural-vector space.

INTERPRETATION TARGETS:
The bridge should answer:

1. Do pre-collapse radial structures and post-collapse light-curve responses
   occupy clearly separated structural regimes?

2. Are any B light-curve objects closer to the A pre-collapse region than the
   rest?

3. Does SN2012aw remain special when compared against A?

4. Does A2_20M, the stronger 20M pre-supernova profile case, align more closely
   with any B object than A1_12M?

5. Does the result support a boundary-transition interpretation:
   pre-boundary connected radial structure
   → boundary event
   → post-boundary observable relaxation trajectory?

IMPORTANT LIMITATIONS:
Do not claim direct causal prediction from A to B.

Phase A profiles are terminal/pre-supernova radial structures, not full
time-resolved stellar histories.

Phase B light curves are observable post-collapse brightness responses, not
direct measurements of the hidden stellar core.

The bridge is structural and comparative, not a full astrophysical explosion
model.

VALID CLAIM IF RESULTS SUPPORT IT:
A and B can be compared as two processed structural-vector domains:
pre-boundary radial support/composition structure and post-boundary observable
relaxation response.

INVALID CLAIMS:
Do not claim that the pre-supernova profile alone predicts a specific
supernova light curve.

Do not claim that two A profiles represent all massive-star pre-collapse
behavior.

Do not claim that six B light curves represent all core-collapse supernovae.

UNNS INTERPRETATION:
A–B bridge tests whether the dataset begins to show a structural transition
from support-bearing pre-collapse configurations into post-collapse relaxation
basins.

In UNNS terms:

Phase A:
pre-boundary radial configuration inside the stellar support ladder.

Phase B:
post-boundary brightness-response trajectory after collapse/explosion.

Bridge:
comparison of the two processed domains in reviewed structural-vector space.

STATUS:
Phase A v2 vector summary exists.
Phase B v2 vector summary exists.
A–B bridge folder initialized.
Ready for tools/ab_bridge_compare.py.
