A conjugation-aligned transcendental admits no algebraic multiple of algebraic norm
ProvedDiaz.elliptic_torsion_excludedSource. Part (c) of Carlo Perassi's elliptic axis and alignment lemma, from a transfer of his argument to elliptic curves, unpublished apart from this node: in the complex multiplication case, the elliptic Diaz locus contains no elliptic logarithm of a torsion point.
Statement, as formalised. Let ω ∈ ℂ be non-algebraic with conj ω = λ ω for some
algebraic λ, and let α be a non-zero algebraic number. Then (α ω) * conj (α ω) is not
algebraic.
Why this is the lemma's statement. The lemma's torsion logarithms are the
elements of , which in the complex-multiplication case is
for a period ; reality of the invariants gives
and hence with ,
and Schneider's theorem says a non-zero period is transcendental. The conclusion is that
with never satisfies . Substituting the two inputs — " transcendental" and
"" — for the objects they constrain gives exactly the
formal statement, with λ and α arbitrary algebraic numbers rather than elements of the
endomorphism field. As with part (b), the substitution loses nothing and needs no definition
of the period lattice or of the elliptic logarithm set.
The proof. α ω is not algebraic (else ω = (αω)/α would be), and
conj (α ω) = (conj α · λ / α) · (α ω) with the multiplier algebraic; the alignment lemma
(Diaz.elliptic_axis_alignment, parts (a),(b)) then rules out an algebraic norm.
Not in the companion note. This statement is not in Carlo Perassi's companion note to https://github.com/carlok/diaz-modulus-lean (version 1.9, 25 September 2026, GitHub release note-v1.9). It was left out for scope: the note treats the Diaz locus, not the consequences of the same machinery for all logarithms or the transfers to elliptic and p-adic settings. Nothing was withdrawn as wrong: the transfers were moved out, not retracted.
Novelty. No novelty is claimed, either for the mathematics or for the formalisation. Carlo Perassi presents these statements as transfers of a complex argument to another setting.
import Mathlib import Definitions.Def_Diaz_Closure import Definitions.Def_Diaz_Instantiation open ComplexConjugate open Diaz
theorem Diaz.elliptic_torsion_excluded {ω lam α : ℂ} (hω : ¬ IsAlgebraic ℚ ω)
(hlam : IsAlgebraic ℚ lam) (hcω : conj ω = lam * ω)
(hα : IsAlgebraic ℚ α) (hα0 : α ≠ 0) :
¬ IsAlgebraic ℚ ((α * ω) * conj (α * ω)) := by sorry