This file defines the class of perturbations V allowed in the Spectral Gap Rigidity Wall.
All rigidity results depend only on this definition.
An admissible V must satisfy:
-
Symmetry:
- Preserves the automorphism group of the base structure.
- Commutes with all global symmetries of A.
-
Locality:
- Acts only on bounded-radius neighborhoods.
- No long-range couplings.
-
Uniformity:
- Same action on all isomorphic local patches.
- No position-dependent bias.
-
Boundedness:
- A-bounded in operator norm.
The following are not admissible:
- Diagonal defects.
- Local weight injections.
- Any perturbation that singles out a vertex or cycle.
- Any perturbation that breaks translational invariance.
Given this class of V, determine whether:
Pi V Pi = 0 holds for all admissible V.
This is the entire URF-SG wall.