# BC_BRIDGE_INDEX.txt
# STELLAR_BOUNDARY_DYNAMICS_I
# B–C Bridge — Light-Curve Response vs Spectral Line Evolution

BRIDGE:
B–C

PARENT DATASET:
stellar_boundary_dynamics

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

This bridge asks whether post-collapse brightness-response trajectories and
post-collapse spectral element-line evolution trajectories occupy compatible,
separated, or object-dependent regions of structural-vector space.

PHASE B:
B_supernova_light_curves

PHASE B DATA TYPE:
Observed post-collapse supernova light-curve response data.

PHASE B SOURCE:
Open Supernova Catalog / AstroCats-derived JSON light-curve data.

PHASE B OBJECTS:
B_SN1987A
B_SN1993J
B_SN1999em
B_SN2011dh
B_SN2012aw
B_SN2013ej

PHASE B PROCESSING CHAIN:
raw supernova JSON
→ light-curve ladder CSV
→ STRUC-PERC-I canonical input
→ numeric STRUC-PERC-I ladder
→ STRUC-PERC-I batch result
→ alpha-application grid
→ first-pass 5D vector
→ 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 REVIEW STATUS:
Comparable objects: 1
Scale-review-needed objects: 5
High-tail/high-kappa attention objects: 1

PHASE B SPECIAL CASE:
SN2012aw remained the main high-tail/high-kappa attention object in the
light-curve layer.

PHASE C:
C_spectral_time_series

PHASE C DATA TYPE:
Observed post-collapse spectral time-series data converted into spectral
line-window structural ladders.

PHASE C SOURCE:
WISeREP public spectra.

PHASE C PILOT OBJECTS:
C1_SN1993J
C2_SN2012aw

PHASE C PROCESSING CHAIN:
raw WISeREP spectra
→ spectral line-window ladder CSV
→ STRUC-PERC-I canonical input
→ numeric STRUC-PERC-I ladder
→ STRUC-PERC-I batch result
→ alpha-application grid
→ first-pass 5D vector
→ normalization-reviewed v2 vector

PHASE C REQUIRED BRIDGE INPUT:
../C_spectral_time_series/alpha_application/normalization_review/C_5D_VECTOR_SUMMARY_v2.csv

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

PHASE C SPECIAL CASE:
C2_SN2012aw remained a high-tail/high-kappa attention object in the spectral
layer.

BRIDGE INPUTS:
inputs/B_5D_VECTOR_SUMMARY_v2.csv
inputs/C_5D_VECTOR_SUMMARY_v2.csv

RECOMMENDED LOCAL INPUT COPIES:
Copy:

B_supernova_light_curves/alpha_application/normalization_review/B_5D_VECTOR_SUMMARY_v2.csv

to:

BC_bridge/inputs/B_5D_VECTOR_SUMMARY_v2.csv

Copy:

C_spectral_time_series/alpha_application/normalization_review/C_5D_VECTOR_SUMMARY_v2.csv

to:

BC_bridge/inputs/C_5D_VECTOR_SUMMARY_v2.csv

BRIDGE OUTPUT STRUCTURE:
BC_bridge/
  BC_BRIDGE_INDEX.txt

  inputs/
    B_5D_VECTOR_SUMMARY_v2.csv
    C_5D_VECTOR_SUMMARY_v2.csv

  comparisons/
    BC_VECTOR_PAIRWISE_COMPARISON.csv
    BC_DOMAIN_CENTROID_COMPARISON.csv
    BC_OBJECT_ALIGNMENT.csv

  summaries/
    BC_BRIDGE_SUMMARY.csv
    BC_BRIDGE_INTERPRETATION.txt
    BC_BRIDGE_RESULT_RECORD.txt

NEXT SCRIPT:
tools/bc_bridge_compare.py

SCRIPT INPUTS:
BC_bridge/inputs/B_5D_VECTOR_SUMMARY_v2.csv
BC_bridge/inputs/C_5D_VECTOR_SUMMARY_v2.csv

SCRIPT OUTPUTS:
BC_bridge/comparisons/BC_VECTOR_PAIRWISE_COMPARISON.csv
BC_bridge/comparisons/BC_DOMAIN_CENTROID_COMPARISON.csv
BC_bridge/comparisons/BC_OBJECT_ALIGNMENT.csv
BC_bridge/summaries/BC_BRIDGE_SUMMARY.csv
BC_bridge/summaries/BC_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.

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

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

OBJECT ALIGNMENT TARGET:
Because Phase C currently contains only two pilot objects, the first B–C bridge
should prioritize object-matched comparison where possible:

B_SN1993J ↔ C1_SN1993J
B_SN2012aw ↔ C2_SN2012aw

The bridge should also compute pairwise distances from all B objects to both C
pilot objects, but the object-matched pairs are the most meaningful first
diagnostic.

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

2. Object-matched alignment
   Extract direct comparisons:
   B_SN1993J ↔ C1_SN1993J
   B_SN2012aw ↔ C2_SN2012aw

3. Domain centroid comparison
   Compute B-domain centroid and C-domain centroid in normalized v2 feature
   space.

4. Special-case persistence test
   Check whether SN2012aw remains special in both B and C.

INTERPRETATION TARGETS:
The bridge should answer:

1. Does the light-curve layer and spectral layer preserve the same contact /
   outlier pattern?

2. Does SN1993J remain less extreme in both B and C?

3. Does SN2012aw remain the high-tail/high-kappa special case in both B and C?

4. Are light-curve response vectors closer to spectral vectors for the same
   object than to other objects?

5. Does the B–C bridge support a multi-observable post-collapse relaxation
   interpretation?

IMPORTANT LIMITATIONS:
Do not claim that spectral line-window proxies are direct abundance
measurements.

Do not claim radiative-transfer modeling.

Do not claim that the two-object Phase C pilot represents all spectral behavior.

Do not claim direct physical causation from vector proximity alone.

VALID CLAIM IF RESULTS SUPPORT IT:
B and C can be compared as two post-collapse observational layers:
brightness-response trajectories and spectral element-line evolution
trajectories.

The bridge can test whether the SN2012aw outlier status persists across
independent observational representations.

INVALID CLAIMS:
Do not claim that spectra alone identify the progenitor profile.

Do not claim nucleosynthesis yield recovery.

Do not claim object-by-object explosion prediction.

UNNS INTERPRETATION:
The B–C bridge tests whether two post-boundary observables share a common
structural relaxation signature.

Phase B:
brightness-response ladder

Phase C:
spectral line-evolution ladder

Bridge:
comparison of post-collapse relaxation geometry across independent observable
channels.

EXPECTED ATTENTION CASE:
SN2012aw should be treated as a sensitivity/outlier candidate.

If B_SN2012aw and C2_SN2012aw both remain high-tail/high-kappa, this supports
the claim that the object’s special status is not only a light-curve artifact.

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