Feeding the weighted trace bound into maximal-divisor escape #
The general Corvaja--Zannier theorem already provides a uniform estimate for all finite multiplicative subgroups. This adapter applies it only to the divisibility-maximal right subgroups required by the improved middle game.
theorem
BGS.Markoff.exists_iterate_with_larger_secondRotationOrder_of_nonzero_nonparabolic_maximalOrders
(p : ℕ)
[Fact (Nat.Prime p)]
[Fintype (quadraticFiniteField p)]
(hpTwo : p ≠ 2)
(delta : ℝ)
(hdelta : delta ≤ 1 / 2)
(x : NormalizedPoint (ZMod p))
(hx : IsNormalizedMarkoff x)
(hnonzero : x.u1 ≠ 0)
(hnonparabolic : x.u1 ^ 2 ≠ 4)
(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 :
∀ (w s : (quadraticFiniteField p)ˣ),
↑w ^ 2 ≠ 1 →
algebraMapNormalizedPoint p x = splitFiberPoint w s →
↑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
Diagonalize a nonzero nonparabolic fiber and apply the maximal-order escape theorem.
theorem
BGS.Markoff.exists_iterate_with_larger_secondRotationOrder_of_weightedTraceBound_maximalOrders
(p : ℕ)
[Fact (Nat.Prime p)]
[Fintype (quadraticFiniteField p)]
(hpTwo : p ≠ 2)
(delta : ℝ)
(hdelta : delta ≤ 1 / 2)
(x : NormalizedPoint (ZMod p))
(hx : IsNormalizedMarkoff x)
(hnonzero : x.u1 ≠ 0)
(hnonparabolic : x.u1 ^ 2 ≠ 4)
(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)
(hBound : WeightedTraceTorsionIntersectionBound p (quadraticFiniteField p))
:
∃ (n : ℕ), rotationOrder x.u1 < rotationOrder (normalizedRotate1^[n] x).u2
The in-repository weighted torsion-intersection theorem supplies every maximal-order estimate needed by the improved escape step.