1076 — The Leading Yukawa Triangle Is Exact Chart Data and Does Not Descend Through Masses + : the Mechanism, the Cross-Check Floor, and an S43/S47 Source Discrepancy
Question
WP4 of the flavor admission brief: isolate the smallest exact mechanism behind "Yukawa triangle CKM unitarity triangle at leading order", reproduce one NLO correction exactly, and decide whether the leading triangle descends through the physical (masses, ) submap — the sharpened form of Nima's ev-703 critical-locus test and the readout half of Benincasa's ev-704 question.
1. S38 (Example I): , exact and validated
Exact truncated- series pipeline (characteristic-polynomial invariants , iterated smallest root, sum/product for the remaining roots, adjugate-column eigenvectors with overall -scale stripping; truncation ; symbolic throughout; no floats). For texture S38 at symbolic :
so EXACTLY, and the leading magnitude is precisely the Eq. (6) link ratio (verified as a typed identity, not a fit). The correction to the angle matches the supplement's printed (S42) formula at , , as an exact symbolic identity. All six leading mass eigenvalues match (S41) including the seesaw .
Independent numeric certification (60-digit mpmath eigensystems of the exact texture, declared rational edge values, and , Richardson extraction): the S38 angle deviation from scales as (rate ratio ) and the extracted coefficient agrees with (S42) to 9 significant digits.
2. The identity and its series floor
Two independent computations of the Jarlskog invariant:
- from the series eigenvectors;
- from the exact polynomial determinant (no truncation) and eigenvalue-difference series (no eigenvectors).
They agree through (relative past the lead); the first divergence at sits exactly at the series-eigenvector precision floor of the -scale eigenvalue at , and does not move between and (the floor is set by adjugate-column conditioning, not the global truncation). The identity itself is the textbook-exact commutator relation; what WP4 adds is the certified agreement window and the exact sine form of the lead: with (exponent vector ).
3. Descent verdict: the leading triangle is chart-fiber data
Exponent-lattice test on the leading monomials (basis , plus the -degree):
- the six mass vectors span a rank-6 lattice;
- adjoining the sine-coefficient vector raises the rank to 7;
- the leading side ratio (exponent vector ) lies in NEITHER span.
So the leading Yukawa-triangle side ratio is not a function of the six masses, and not a function of (masses, ). Combined with Entry 1054's involution audit — the (masses, ) submap has the two-point fiber while changes under — the leading ANGLE is chart-fiber data as well. Hence:
The almost- mechanism isolated in Entries 1047–1048 ( at LO through the viability equation) is therefore a chart-space identity: the physical readout receives only through and the full invariant map, and the clustering remains presentation-ensemble evidence modulo the viability sampling. This answers Nima's ev-703 in the negative at leading order: there is no invariant critical locus carrying the cluster; the cluster lives on chart fibers. It also sharpens Benincasa's ev-704: whatever glues under the support groupoid, the readout side of the lens–readout pair must be built from the full invariant map, not from the leading triangle.
4. S43 (Example II): LO confirmed numerically; the printed NLO is not reproducible
Symbolic S43 remains intractable for the series pipeline (seesaw scales with 16th-root-of-unity radicals at ; the eigensystem does not complete at within 20 minutes). The 60-digit numeric pipeline instead gives, for the standard quartet :
i.e. exactly (orientation-convention sign), confirming the LO phase-angle tie in a second texture.
However, the exact computation gives a VANISHING correction, while the supplement's (S47) prints (\beta\simeq\frac{\pi}{8}-\frac12\sqrt{2-\sqrt2}, \frac{d_{13}d_{23}^2d_{33}u_{33}}{(d_{32}^2+d_{33}^2)^2u_{13}}\epsilon^2). The printed S43 CKM block is internally inconsistent under checking: (S47)'s contradicts (S44)'s and the direct texture computation ( from ); (S45)'s contradicts (S47)'s . The pipeline itself is validated end-to-end on S38/S42 (exact symbolic identity plus 9-digit numeric agreement), so the mismatch is logged as an OPEN SOURCE DISCREPANCY in the S43/S47 transcription or expansion, not as a counterexample to the LO mechanism. A correct symbolic S43 NLO derivation remains open.
5. WP4 disposition
- LO angle chart phase: PROVEN (S38 exact symbolic) and confirmed in a second texture (S43, 60-digit numeric, LO exact).
- NLO calculable and matches the source where the source is self-consistent (S38 vs S42: exact). S43/S47: open discrepancy, itemized above.
- The LO triangle (sides AND angle) does not descend through (masses, ): exact exponent-lattice rank test plus the Entry-1054 fiber audit.
- Consequence for admission: the flavor lens–readout package cannot use the Yukawa triangle as readout; the candidate readout remains the weak-basis invariant map, with entering through and the CP-even mixed invariants (1054). The phenomenon stays chart-ensemble evidence.
Artifacts and reproduction
research/flavor/checkers/wp4_triangle_lo.py(exact series pipeline; runPYTHONPATH=checkers .venv/Scripts/python checkers/wp4_triangle_lo.py --s38-only), outputresearch/flavor/results/wp4_triangle_lo.json.research/flavor/checkers/wp4_numeric_angle.py(60-digit cross-check, both textures; declared rational edge assignment printed in the output), outputresearch/flavor/results/wp4_numeric_angle.json.research/flavor/checkers/wp4_ratio_scan.py,wp4_s43_elements.py,wp4_s43_probe.py(S43 diagnostics behind section 4).- Sequence authority: seqclaim-c16a9286646f9cf141e039d8 (value 1076).