Compensation for tests measurable in the stopped past at a deterministic local-time level.
See Bertoin, Lévy Processes, Chapter IV, and Kallenberg, Foundations of Modern Probability, Chapters 12 and 22.
theorem
BGW.StableTrees.lintegral_excursionPointMeasure_window
{θ : ℝ}
(hθ : 1 < θ ∧ θ ≤ 2)
{a b : NNReal}
(hab : a ≤ b)
{A : Set Excursion}
(hA : MeasurableSet A)
:
∫⁻ (f : Skorokhod.DLoc), (excursionPointMeasure f) (Set.Ioc a b ×ˢ A) ∂↑(stableLocalLaw θ) = ↑(b - a) * (excursionMeasure θ) A
The mean window formula also holds for the original point measure.
theorem
BGW.StableTrees.indepFun_stopped_future_excursionPointMeasure
{θ : ℝ}
(hθ : 1 < θ ∧ θ ≤ 2)
(a : NNReal)
{Y : Skorokhod.DLoc → ENNReal}
(hY : Measurable Y)
:
ProbabilityTheory.IndepFun Y
(fun (f : Skorokhod.DLoc) => excursionPointMeasure (Skorokhod.DLoc.shiftAt (firstPassageBelow a) f))
↑(stableLocalLaw θ)
The future marked process is independent of every test measurable in the stopped past.
theorem
BGW.StableTrees.excursion_compensation_step
{θ : ℝ}
(hθ : 1 < θ ∧ θ ≤ 2)
{a b : NNReal}
(hab : a ≤ b)
{A : Set Excursion}
(hA : MeasurableSet A)
{Y : Skorokhod.DLoc → ENNReal}
(hY : Measurable Y)
:
∫⁻ (f : Skorokhod.DLoc), Y f * (excursionPointMeasure f) (Set.Ioc a b ×ˢ A) ∂↑(stableLocalLaw θ) = (∫⁻ (f : Skorokhod.DLoc), Y f ∂↑(stableLocalLaw θ)) * (↑(b - a) * (excursionMeasure θ) A)
Step compensation relative to F_{T_a}: for Y measurable in the stopped σ-algebra of
T_a (not merely the natural history of the point measure), a ≤ b, measurable A:
E[Y · μ((a,b] × A)] = E[Y] (b - a) N(A).