Uniform control of aligned Vervaat transforms #
After aligning the minimizing times, rotation preserves uniform path control. The two endpoint values and the infimum account for the additional errors.
theorem
BGW.Skorokhod.exists_vervaat_timeChange_bound
(u f : D 1 ℝ)
(ρ : TimeChange 1)
(halign : ρ (vervaatTime f) = vervaatTime u)
{d e : ℝ}
(hd : ∀ (t : ↑(Set.Icc 0 1)), |↑(ρ t) - ↑t| ≤ d)
(hp : ∀ (t : ↑(Set.Icc 0 1)), dist (u (ρ t)) (f t) ≤ e)
(hm : dist (⨅ (s : ↑(Set.Icc 0 1)), u s) (⨅ (s : ↑(Set.Icc 0 1)), f s) ≤ e)
:
Rotating an aligned approximation controls both the time and path errors.