Full-sequence coupling for localized long-block extraction #
The compact-horizon FCLT is represented along the entire sequence. Graph disintegration lifts the limit to the local stable law. Reconstructed mesh increments then satisfy the long-block extraction convergence on the first-long-mark good event, with no subsequence change of the mesh index.
theorem
BGW.StableTrees.TailPair.exists_localized_pair_coupling
{μ : PMF ℕ}
{θ : ℝ}
{B : ℕ → ℝ}
(h : StableDomain μ θ B)
(M T : NNReal)
(hM : 0 < M)
(hT : 0 < T)
:
∃ (η : MeasureTheory.ProbabilityMeasure (↑unitInterval × Skorokhod.DLoc)) (Y :
ℕ → ↑unitInterval × Skorokhod.DLoc → Skorokhod.D ↑M ℝ × C(↑(Set.Icc 0 ↑M), ℝ)),
(∀ (n : ℕ), Measurable (Y n)) ∧ (∀ (n : ℕ),
MeasureTheory.Measure.map (Y n) ↑η = ↑((DiscreteForest.offspringSeqLaw μ).map (DiscreteForest.forestPairPath B n M))) ∧ MeasureTheory.Measure.map Prod.snd ↑η = ↑(stableLocalLaw θ) ∧ ∀ᵐ (p : ↑unitInterval × Skorokhod.DLoc) ∂↑η, Filter.Tendsto (fun (n : ℕ) => Y n p) Filter.atTop
(nhds (Skorokhod.DLoc.restrict M p.2, heightPrefix θ M (Skorokhod.DLoc.restrict M p.2))) ∧ (∀ (n i : ℕ), IsSkipFreeIncrement (PathTail.reconstructIncrements M n (B n) (Y n p).1 i)) ∧ (passageTime (firstLongLabel p.2) p.2 < M →
Filter.Tendsto
(fun (n : ℕ) => extractionTriple (B n) n T (PathTail.reconstructIncrements M n (B n) (Y n p).1))
Filter.atTop (nhds (longCutTriple T p.2)) ∧ ∀ᶠ (n : ℕ) in Filter.atTop, firstLongIndex n (PathTail.reconstructIncrements M n (B n) (Y n p).1) ∈ longBlockSet n (PathTail.reconstructIncrements M n (B n) (Y n p).1) ∧ ladderTime (PathTail.reconstructIncrements M n (B n) (Y n p).1)
(firstLongIndex n (PathTail.reconstructIncrements M n (B n) (Y n p).1) + 1) ≤ ⌊↑n * ↑M⌋₊)
A full-sequence compact-path coupling with a local stable limit, reconstructed skip-free
increments, and long-block extraction convergence on the event that the limiting end precedes
M.