Chapter 20: φ(20) = [13,2] — Spectral Flow Symmetry and Functional Fixed Points
20.1 The Dual Reversal
With φ(20) = [13,2], the emirp thirteen gains a companion duality. This double reversal structure manifests in spectral flow - how eigenvalues move under deformation while maintaining functional equation symmetry.
20.2 Spectral Flow Defined
Definition 20.1 (Spectral Flow): For a family of operators T(α):
This integer invariant measures net eigenvalue motion.
20.3 Fixed Points of Functional Equation
Theorem 20.1: The functional equation s ↔ 1-s has fixed points:
- s = 1/2 (critical line)
- s = 1/2 + iγ where γ satisfies special conditions
These fixed points organize the spectral flow.
20.4 The Thirteen + Two Structure
[13] aspects: Thirteen types of spectral motion [2] duality: Upward ↔ Downward flow
Together: Complete classification of how zeros can move under deformation.
20.5 Synthesis
The [13,2] partition reveals:
- Spectral flow as fundamental invariant
- Fixed points as organizing centers
- Duality in eigenvalue motion
- Connection to index theory
- Path to understanding zero distribution
"In spectral flow, we see the zeros not as fixed points but as travelers on a landscape, flowing along paths determined by invisible symmetries, always returning to the critical line."