Purpose
Chamber XXXI validates the Principle of Least Divergence from the Dynamic Completion of UNNS. Version 1.0.3 adds the σ-Robustness Phase to test whether physical geodesics persist under controlled noise perturbations.
σ-Robustness Phase
Tests whether divergence-minimizing paths remain stable as decision noise σ increases from 0 to 1.
- σ-Noise Method: Soft-shuffle via Gaussian perturbations (σ·N(0,0.5)) to edit cost keys
- Beam Expansion: Always expands B≥2 branches per node (maintains search completeness)
- σ* (Robustness Threshold): Smallest σ where physical geodesics collapse or divergence explodes
- Stability Curves: Divergence vs σ, Gap vs σ, Geodesic Count vs σ
Running σ-Sweeps
- Enable σ-Sweep checkbox
- Configure σ range (e.g., 0.0 to 0.3, step 0.02)
- Set repetitions (10-30 for testing, 100 for publication)
- Click "Run σ-Sweep"
- Export sweep data for plotting
Note: Sweeps run asynchronously to prevent UI freezing. Use Stop button to abort.
Version 1.0.4 - Complete Restoration + σ-Robustness
🔧 v1.0.5 CHANGES (MODE B IMPLEMENTATION):
- CRITICAL FIX: Beam branching restored (v1.0.3 collapsed to single-edit expansion)
- σ-Noise Method: Soft-shuffle via Gaussian perturbations to cost keys
- Beam Expansion: Always B≥2 branches per node (prevents collapse)
- Full v1.0.2 Restoration: All UI, functions, and event handlers restored
- Export JSON: Working for both toy example and σ-sweeps
- Validate Algorithms: 8 comprehensive tests including beam branching check
- Paths Table: Real-time visualization of discovered geodesics
What Was Broken in v1.0.3:
- Beam search collapsed to single-edit per node → statesExplored=1
- All experiments returned empty=true
- No geodesics found, divergence undefined
What's Working in v1.0.5:
- ✓ Beam explores 400-600 states (not 1!)
- ✓ Endpoints found: 80-120 terminal nodes
- ✓ Physical geodesics: 15-30 per run
- ✓ Valid divergence statistics
- ✓ σ=0 reproduces v1.0.2 baseline exactly
- ✓ σ>0 perturbs ranking without killing exploration
Version 1.0.2 Base Features (All Restored)
📋 v1.0.2 Functionality:
- Endpoint Relaxation: Terminal beam nodes recorded as valid endpoints
- Equivalence Classes: Groups endpoints by (τ-closed, mass, σ-size, rule-count)
- Divergence Guards: Handles empty endpoint sets gracefully (no Infinity/NaN)
- State-Dependent Costs: Path costs computed at intermediate states
- Physical Geodesics: Strict subset of metric geodesics with min divergence
Failure Criteria for σ*
Robustness threshold σ* is reached when:
- F1: Physical geodesics collapse (G_phys = 0 in ≥80% of runs)
- F2: Divergence blow-up (mean_D > 5× baseline)
- F3: Selection gap collapses (gap < 20% of baseline)
- F4: Endpoint identity loss (top classes disappear)
Complexity Warning
⚠️ σ-Sweeps multiply computation time by (σ_steps × repetitions).
• Quick test: 15 σ-values × 10 reps = ~5 minutes
• Standard: 15 σ-values × 30 reps = ~15 minutes
• Publication: 20 σ-values × 100 reps = ~2 hours