Scaling law of the constructed auxiliary clock #
The positive-filter convergence in mean identifies dilated occupations with the clock. No invariance of the particular fast cutoff sequence is asserted or needed.
References #
- J. Bertoin, Lévy Processes, Cambridge University Press, 1996, Chapter IV.
theorem
BGW.StableTrees.integral_scaleLoc
{θ : ℝ}
(hθ : 1 < θ ∧ θ ≤ 2)
(c : ↑(Set.Ioi 0))
{G : Skorokhod.DLoc → ℝ}
(hG : MeasureTheory.Integrable G ↑(stableLocalLaw θ))
:
∫ (f : Skorokhod.DLoc), G (scaleLoc θ c f) ∂↑(stableLocalLaw θ) = ∫ (f : Skorokhod.DLoc), G f ∂↑(stableLocalLaw θ)
Stable path dilation preserves the expectation of any integrable scalar observable.
theorem
BGW.StableTrees.ae_supAuxLocalTime_scaleLoc
{θ : ℝ}
(hθ : 1 < θ ∧ θ ≤ 2)
(c : ↑(Set.Ioi 0))
(t : NNReal)
:
(fun (f : Skorokhod.DLoc) => supAuxLocalTime θ (scaleLoc θ c f) t) =ᵐ[↑(stableLocalLaw θ)] fun (f : Skorokhod.DLoc) =>
↑c / ↑c ^ (1 / θ) * supAuxLocalTime θ f (t / (↑c).toNNReal)
Clock scaling at each deterministic time follows from occupation scaling in mean.
theorem
BGW.StableTrees.map_supAuxLocalTime_scaling
{θ : ℝ}
(hθ : 1 < θ ∧ θ ≤ 2)
(c : ↑(Set.Ioi 0))
(t : NNReal)
:
MeasureTheory.Measure.map (fun (f : Skorokhod.DLoc) => supAuxLocalTime θ f t) ↑(stableLocalLaw θ) = MeasureTheory.Measure.map (fun (f : Skorokhod.DLoc) => ↑c / ↑c ^ (1 / θ) * supAuxLocalTime θ f (t / (↑c).toNNReal))
↑(stableLocalLaw θ)
The one-time clock laws have the stable local-time scaling factor.