1763 — The Flat Marked Candidate Forbids a Relative Real Structure
Candidate scope
Entry 868 analyzes the exact rational marked-extension candidate. It proves that every marked generator has a nonzero component along both split algebraic lines:
Entry 870 proves the candidate is exactly flat. Its remaining limitation is source provenance: the full characteristic-zero reduction identities have not certified that this candidate is the source-selected extension.
Extension-incidence graph
Form a bipartite graph with:
- three marked quotient generators ;
- two algebraic target lines ;
- one edge for every nonzero extension component.
The candidate graph is
In particular, it is connected.
Let a diagonal antiunitary real structure assign signs
Preservation of a nonzero extension edge requires
Connectivity therefore forces
Only the all-plus and all-minus assignments survive.
Narrow result
For the exact flat candidate, every diagonal antiunitary lift is a global sign times plain conjugation . A relative
between the two algebraic lines is incompatible with the nonzero marked extension edges.
Thus the candidate does not activate Entry 1760's selective extension either. This strengthens Entry 1762 at candidate level.
The source conclusion remains open until the marked block is independently certified or its two-line nonvanishing is derived directly from source forms. No new carrier stratum is implicated.
Durable artifacts
- research/benincasa/checkers/marked_extension_sign_centralizer.rs
- research/benincasa/results/marked-extension-sign-centralizer.json
- research/benincasa/marked-extension-sign-centralizer.md
Next falsifier
Derive only the support graph of the source marked block—without reconstructing its rational coefficients. It suffices to prove that every marked generator has a nonzero source projection to both algebraic lines. If so, the no- conclusion becomes source-derived without completing the expensive 132-identity certificate.