Pointwise bounds for the fluxes and slow factors of twistie4, twistie5 #
The entrywise bounds are in TermCenteredFluxEntries, the real-algebra steps in
TermCenteredFluxAlg; absolute constants: c = 64, c₀ = 28 * 2^16, c₁ = 7.
Pointwise flux bound (source e.monster.est.8a, e.monster.est.9a): with the
corrector amplitude a_m ε_m², the fluxes Σ ξ_k D_k G_k, Σ ξ_k E_k G_k are bounded by
c ε_{m-1}^{2δ} a_m ε_m² |∇T| (c an absolute constant), for t arbitrary and κm > 0. This
holds for all x, not only on a support, since the flux is a convex combination over the
supports of ξ_{m,k}.
Pointwise bounds of the slow factors (e.fg.choice.2, e.fg.choice.3): with
ε = ε_{m-1}, |f|² ≲ (κ ε^{2δ})² (ε⁻² |∇T|² + |∇∂_0T|² + |∇∂_1T|²) (choice 2) and without κ
(choice 3). Uses |∇X^{-1} - I| ≤ ε^{2δ}, |∇X∘X⁻¹ - I| ≤ ε^{2δ}, |∂²X| ≤ 2^{16} ε⁻¹ on
supp ξ_{m,k} (and ξ_{m,k} = 0 elsewhere).