Quantitative lattice counting for a finite Lipschitz boundary #
A bounded subset of real coordinate space whose boundary is covered by finitely
many m-parameter Lipschitz charts has lattice discrepancy O(t^m) under
dilation by t. All chart and boundedness hypotheses are explicit.
theorem
NairTenenbaum.exists_lipschitz_boundary_lattice_discrepancy
{ι : Type u_1}
{κ : Type u_2}
{J : Type u_3}
[Fintype ι]
[Fintype κ]
[Finite J]
{s : Set (ι → ℝ)}
(hs : Bornology.IsBounded s)
(f : J → (κ → ℝ) → ι → ℝ)
(L : J → NNReal)
(hf : ∀ (j : J), LipschitzOnWith (L j) (f j) (Set.Icc (fun (x : κ) => 0) fun (x : κ) => 1))
(hcover : ∀ y ∈ frontier s, ∃ (j : J), ∃ x ∈ Set.Icc (fun (x : κ) => 0) fun (x : κ) => 1, f j x = y)
:
∃ (C : ℝ),
0 ≤ C ∧ ∀ (t : ℝ),
1 ≤ t →
|↑(integerLatticeCount (t • s)) - t ^ Fintype.card ι * MeasureTheory.volume.real s| ≤ C * t ^ Fintype.card κ