Documentation

LeanPool.ErdosGinzburgZiv.EGZ.Expansion.RelativeProof

Relative expansion #

The thresholds are first chosen for a fixed finite lattice support, then made uniform over every support in the prescribed box. All sampling and deletion arguments retain the positions of repeated vectors.

theorem EGZ.Expansion.relative_expansion_fixed_support {r t : ℕ} (ht : 0 < t) (S : Finset (IntCoord r)) (hS : S.Nonempty) (δ : ℝ) (hδ : 0 < δ) :
∃ (T₀ : ℕ) (p₀ : ℕ), ∀ (T : ℕ), T₀ ≤ T → ∀ (p : ℕ), Fact (Nat.Prime p) → ∀ (x : NeZero p), p₀ ≤ p → (Function.Injective fun (q : ↥S) => IntCoord.mod p ↑q) → ∀ (w : FpCoord p (r + t) → ℕ) (α : ↥S → ℤ), (∀ (v : FpCoord p (r + t)), w v ≠ 0 → ∃ (q : ↥S), (Coord.first r t) v = IntCoord.mod p ↑q) → ∑ q : ↥S, α q • ↑q = 0 → ∑ q : ↥S, α q = ↑p → (∀ (q : ↥S), δ * ↑p ≤ ↑(α q) ∧ ↑(α q) ≤ ↑(pushWeight (⇑(Coord.first r t)) w (IntCoord.mod p ↑q)) - δ * ↑p) → IsThickRelative w (⇑(Coord.first r t)) T δ → HasZeroSumMultiplicity w

For one fixed support, the analytic parameters are independent of the prime, the fibre multiplicities and the prescribed coefficients.

The relative expansion theorem, with uniform thresholds for all supports in a fixed integer box.