From residue traces to the concrete cyclotomic opening bound #
This file chooses eigenvalues for arbitrary normalized traces over ZMod p, including the two
parabolic traces, and combines their exact orders by an lcm.
theorem
BGS.Markoff.exists_residueClosure_eigenvalue_of_trace
(p : ℕ)
[Fact (Nat.Prime p)]
(hpTwo : p ≠ 2)
(t : ZMod p)
:
∃ (W : (OpeningResidueClosure p)ˣ),
(algebraMap (ZMod p) (OpeningResidueClosure p)) t = splitTorusTrace W ∧ IsOfFinOrder W ∧ p.Coprime (orderOf W)
Every normalized trace over an odd prime field has a finite-order eigenvalue in the fixed
residue closure. Parabolic traces are represented explicitly by 1 or -1; all other traces
use the split/norm-one classification.
theorem
BGS.Markoff.exists_exact_eigenvalue_orders_with_cyclotomic_bound
(p : ℕ)
[Fact (Nat.Prime p)]
(hpTwo : p ≠ 2)
(x : NormalizedPoint (ZMod p))
(hx : IsNormalizedMarkoff x)
(hxne : x ≠ normalizedOrigin)
:
∃ (W₁ : (OpeningResidueClosure p)ˣ) (W₂ : (OpeningResidueClosure p)ˣ) (W₃ : (OpeningResidueClosure p)ˣ),
(algebraMap (ZMod p) (OpeningResidueClosure p)) x.u1 = splitTorusTrace W₁ ∧ (algebraMap (ZMod p) (OpeningResidueClosure p)) x.u2 = splitTorusTrace W₂ ∧ (algebraMap (ZMod p) (OpeningResidueClosure p)) x.u3 = splitTorusTrace W₃ ∧ IsOfFinOrder W₁ ∧ IsOfFinOrder W₂ ∧ IsOfFinOrder W₃ ∧ p.Coprime (orderOf W₁) ∧ p.Coprime (orderOf W₂) ∧ p.Coprime (orderOf W₃) ∧ p ≤ 20 ^ max (orderOf W₁) (max (orderOf W₂) (orderOf W₃)) ^ 3
Every nonorigin normalized Markoff point over an odd prime field admits three compatible residue-closure eigenvalues. Their exact orders control the concrete cyclotomic opening bound.