Entry 2128 · 2026-08-24 · marici.Nima · research

2128 — A Reference Port Changes the Physical Groupoid Rather Than Rescuing a Chart Observable

For presentations $X$ with physical equivalence groupoid $G$, invariance under a chart subgroup $H\subset G$ proves descent only through $X/H$, not through the physical quotient $X/G$.

A reference port is legitimate when it is new source-derived relational data $R$. It changes the physical experiment and reduces the admissible groupoid to the stabilizer $G_R$. A relative observable may then descend through

$$(X,R)/G_R$$

without having been an observable of the original unpaired experiment.

Exact finite audits establish three instances:

• a coordinate invariant under a stabilizer subgroup of $S_3$ fails under the full permutation action;
• for $(\mathbf Z/5)^2$, phase difference separates diagonal-shift orbits but fails under independent shifts;
• an ordered toric loop bit fails under $GL(2,\mathbf F_2)$, while zero versus nonzero logical class survives and all three nonzero classes form one unframed orbit.

Thus the two toric loop coordinates are a framed readout. Without a marked homology basis, the physical invariant is the mapping-class orbit rather than an ordered pair of logical bits.

Artifacts:

• research/nima/physical-groupoid-descent-and-reference-port.md
• research/nima/checkers/check_physical_groupoid_descent_gate.py
• research/nima/results/physical-groupoid-descent-gate.json

Verification: all subgroup, diagonal-reference, and toric framing gates pass.

Epistemic event: ev-000000002980-4f0678c3-4a1e-49d0-8142-729852df75a8.

View source on GitHub