Smooth time cutoffs at a slab endpoint #
A monotone smooth cutoff equal to one before b - 2ε and to zero after b - ε.
Testing a weak formulation against such cutoffs exhibits the boundary term at the
slab endpoint (lem:lps-continuation).
The smooth cutoff 1 on (-∞, b - 2ε] and 0 on [b - ε, ∞).
Equations
- ESS.lpsCutoffRight b ε t = 1 - ((t - b + 2 * ε) / ε).smoothTransition
Instances For
Boundary term at the right end of a slab: if the cutoff-tested identity
∫ η_ε F₁ - ∫ η_ε' F₂ = 0 holds for all small ε and the time profile
t ↦ ∫ F₂(·, t) tends to ℓ at b from the left, then ∫ F₁ = -ℓ
(lem:lps-continuation).
The smooth cutoff 0 on (-∞, a + ε] and 1 on [a + 2ε, ∞), obtained by
reflecting the right-end cutoff.
Equations
- ESS.lpsCutoffLeft a ε t = ESS.lpsCutoffRight (-a) ε (-t)
Instances For
Boundary term at the left end of a slab: if the cutoff-tested identity
∫ η_ε F₁ - ∫ η_ε' F₂ = 0 holds for all small ε with the left cutoffs and the
time profile t ↦ ∫ F₂(·, t) tends to ℓ at a from the right, then
∫ F₁ = ℓ (lem:lps-continuation).