Identifying discrete and limiting cut-path laws #
K02 identifies the selected closed block with the tail-conditioned tree law. The limiting cut is the first long mark, whose law is the independent tail excursion law.
theorem
BGW.StableTrees.PathTail.map_selectedBlockCut_eq_closedTail
{μ : PMF ℕ}
{θ : ℝ}
{B : ℕ → ℝ}
(h : StableDomain μ θ B)
(n : ℕ)
(T : NNReal)
:
((Probability.RealWalk.iidLaw (realOffspringStepLaw μ)).map fun (ω : ℕ → ℝ) => (extractionTriple (B n) n T ω).2.2) = (DiscreteForest.tailTreeLaw μ n).map fun (τ : LocallyFinite.Tree) =>
Skorokhod.realStepPath (↑T) n (B n) (closedTreeIncrementSeq τ)
The path coordinate of the selected-block triple is the closed path of a tail-conditioned BGW tree, by the exact K02/K04 coding adapter.
theorem
BGW.StableTrees.PathTail.map_longCutTriple_path
{θ : ℝ}
(hθ : 1 < θ ∧ θ ≤ 2)
(T : NNReal)
:
(((stableLocalLaw θ).map (longCutTriple T)).map fun (p : ℝ × ℝ × Skorokhod.D ↑T ℝ) => p.2.2) = tailLevyExcLaw θ T
Projecting the limiting endpoint/cut triple gives the sealed tail excursion path law.