Applying relative expansion to affine fibres #
The relative expansion statement implies an affine-subspace version with uniform thresholds in the original ambient dimension. Translating the integer centre doubles the box radius and changes the weighted sum to zero.
theorem
EGZ.Expansion.AffineModel.apply_relativeExpansion
{p d r t K T : ℕ}
[NeZero p]
[Fact (Nat.Prime p)]
{δ : ℝ}
{V : AffineSubspace (ZMod p) (FpCoord p d)}
{φ : FpCoord p d →ᵃ[ZMod p] FpCoord p r}
(S : Finset (IntCoord r))
(c : IntCoord r)
(M : AffineModel V φ (IntCoord.mod p c) t)
(hexp : RelativeExpansionAt r t (2 * K) δ T p)
(w : FpCoord p d → ℕ)
(α : ↥S → ℕ)
(hbox : ∀ q ∈ S, latticeSupNorm q ≤ K)
(hc : latticeSupNorm c ≤ K)
(hw : ∀ (v : FpCoord p d), w v ≠ 0 → v ∈ V)
(hs : ∀ (v : FpCoord p d), w v ≠ 0 → ∃ q ∈ S, φ v = IntCoord.mod p q)
(hz : ∑ q : ↥S, α q • ↑q = p • c)
(hm : ∑ q : ↥S, α q = p)
(ha : ∀ (q : ↥S), δ * ↑p ≤ ↑(α q) ∧ ↑(α q) ≤ ↑(pushWeight (⇑φ) w (IntCoord.mod p ↑q)) - δ * ↑p)
(hthick : IsThickRelativeOn w (↑V) (⇑φ) T δ)
:
The expansion conclusion for an arbitrary affine surjection on the affine subspace carrying a weight. The centre and support share one box.
Equations
- One or more equations did not get rendered due to their size.
Instances For
theorem
EGZ.Expansion.RelativeExpansionStatement.affine_thresholds
(h : RelativeExpansionStatement)
(d K : ℕ)
(hK : 1 ≤ K)
(δ : ℝ)
(hδ : 0 < δ)
:
Uniformity over the finitely many possible quotient and kernel
dimensions gives thresholds depending only on d, K, and δ.
theorem
EGZ.Expansion.AffineExpansionAt.decomposition
{p d K T : ℕ}
[NeZero p]
{δ δ₀ : ℝ}
(h : AffineExpansionAt d K δ T p)
{f : FpCoord p d → ℕ}
(Φ : FlagDecomposition p d f)
(hp : Odd p)
(x : Φ.flag.Node)
(hr : Φ.flag.rank x ≤ d)
(hbox : ∀ q ∈ Φ.liftedSupport x, latticeSupNorm q ≤ K)
(c : IntCoord (Φ.flag.rank x))
(hc : latticeSupNorm c ≤ K)
(α : ↥(Φ.liftedSupport x) → ℕ)
(hz : ∑ q : ↥(Φ.liftedSupport x), α q • ↑q = p • c)
(hm : ∑ q : ↥(Φ.liftedSupport x), α q = p)
(ha : ∀ (q : ↥(Φ.liftedSupport x)), δ * ↑p ≤ ↑(α q) ∧ ↑(α q) ≤ ↑(Φ.hat x ↑q) - δ * ↑p)
(ht : Φ.IsCompleteElement x T δ₀)
(hδ : δ ≤ δ₀)
:
The expansion interface applies directly to a complete decomposition node. Its conclusion is a zero sum in the original multiplicity function.