← Phase 2 / 24 · Manin / Period Audit
The actual audit results from Referee D, directly resolving the period issue left at the end of document 23. The formula in FW Corollary 1.10 uses the modular-form period, while the elliptic curve's Néron period differs from it by a Manin constant—the document cites modern results: the Manin constant of an optimal parametrization can only be supported by additive reduction primes. For $E_q$, there are exactly two additive primes: $2$ from the base curve itself, and the twist prime $q$. Since FW is only used on the **good supersingular $p$** branch, such $p$ automatically satisfy $p\notin\{2,q\}$, hence $p\nmid c_{E_q}$—the modular period and the Néron period are completely identical in $p$-adic valuation, and the period issue is thus closed. The document then addresses an incidental optimality issue: because the mod-$\ell$ image of the base curve 696.e1 is maximal for all $\ell$, and quadratic twisting preserves residual irreducibility, $E_q$ has no rational prime-degree isogeny—there is no other non-isomorphic curve in its $\mathbb Q$-isogeny class, so $E_q$ itself is automatically the optimal representative, eliminating the need to arbitrarily choose among multiple isogenous models, making this period argument robust.
Relationship with other documents, try to use the words from its own document, not my interpretation.
"E_q itself is the optimal representative, so this period argument does not rely on arbitrarily picking an isogenous model." — Excerpt from the end of the "Optimality" paragraph in this text.
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