Transferring excursion factorization through the exponential clock #
Reference: J. Bertoin, Lévy Processes, Cambridge University Press, 1996, Chapters IV and VI.
theorem
BGW.StableTrees.lintegral_supRunning_supReflected_excursion_factors
{θ : ℝ}
(hθ : 1 < θ ∧ θ ≤ 2)
{q : ℝ}
(hq : 0 < q)
{F G : ℝ → ENNReal}
(hF : Measurable F)
(hG : Measurable G)
:
∫⁻ (p : Skorokhod.DLoc × ℝ), F (supRunning p.1 p.2.toNNReal) * G (supReflected p.1 p.2.toNNReal) ∂expClockLaw θ q = (∫⁻ (f : Skorokhod.DLoc), ∫⁻ (x : NNReal), expNeg (ENNReal.ofReal q * passagePast x f) * G ↑x ∂lebNN ∂↑(stableLocalLaw θ)) * ∫⁻ (e : Excursion), excursionDiscount q F e ∂excursionMeasure θ
The two excursion factors for the supremum and drawdown, before normalization.