Nonparabolic order escape using maximal divisors #
This is the geometric middle-game step with the maximal-divisor cover wired all the way through. The Corvaja--Zannier hypothesis and both numerical inequalities are required only for divisibility-maximal candidate orders.
theorem
BGS.Markoff.exists_iterate_with_larger_secondRotationOrder_of_diagonalizedFiber_maximalOrders
(p : ℕ)
[Fact (Nat.Prime p)]
[Fintype (quadraticFiniteField p)]
(hpTwo : p ≠ 2)
(delta : ℝ)
(hdelta : delta ≤ 1 / 2)
(x : NormalizedPoint (ZMod p))
(w s : (quadraticFiniteField p)ˣ)
(hw : ↑w ^ 2 ≠ 1)
(hpoint : algebraMapNormalizedPoint p x = splitFiberPoint w s)
(hbelowEndgame : ↑(rotationOrder x.u1) < ↑p ^ (1 / 2 + delta))
(hcube :
(corvajaZannierCorollaryTwoSafeCoefficient * (middleGameMaximalOrders p (rotationOrder x.u1)).card) ^ 3 < rotationOrder x.u1)
(hlinear :
corvajaZannierCorollaryTwoSafeCoefficient * (middleGameMaximalOrders p (rotationOrder x.u1)).card * rotationOrder x.u1 < p)
(hCZ :
↑s * (splitFiberProduct w * ↑s⁻¹) ≠ 1 →
∀ d ∈ middleGameMaximalOrders p (rotationOrder x.u1),
↑(weightedTraceEquationSolutions (↑s) (splitFiberProduct w * ↑s⁻¹) (Subgroup.zpowers w)
(middleGameRightSubgroup p d)).card ≤ corvajaZannierTraceUpperBound p (rotationOrder x.u1) (Nat.card ↥(middleGameRightSubgroup p d)))
:
∃ (n : ℕ), rotationOrder x.u1 < rotationOrder (normalizedRotate1^[n] x).u2
Complete nonparabolic order escape from a diagonalized fiber, with the Corvaja--Zannier union restricted to maximal candidate orders.