ConstantBesov #
Ported from scottnarmstrong/Superdiffusion at 7f20476385d4af418f110303085ad0740c9eba46. Module imports, support namespace and local option directives adapted for Lean Pool.
The negative Besov seminorm of a constant vector field #
Source: ABK26, the third summand of the three-way split of ∇u = ∇w + ∇w* + ℓ_p inside e.split.besov.stuff.begin: the affine piece ℓ_p contributes the
constant gradient p, whose concrete negative Besov seminorm is a pure
geometric series.
Every descendant average of a constant field is that constant, so
[c]_{B^{-s}_{2,2}(Q), N} = |c| ( ∑_{j ≤ N} 3^{-2 s j} )^{1/2}
≤ |c| (1 - 3^{-2s})^{-1/2} (0 < s).
The bound is uniform in the depth N, so it also bounds the infinite-depth
sSup seminorm, and it exhibits the required BddAbove witness.
The depth-level quantities of a constant field #
theorem
Algsuperdiff.Section24.Sensitivity.Provider.DhBound.Discharge.cubeBesovNegativeVectorDepthAverage_const
{d : ℕ}
(Q : HCPolySupport.TriadicCube d)
(c : HCPolySupport.Vec d)
(j : ℕ)
:
HCPolySupport.cubeBesovNegativeVectorDepthAverage Q (fun (x : HCPolySupport.Vec d) => c) j = HCPolySupport.vecNormSq c
theorem
Algsuperdiff.Section24.Sensitivity.Provider.DhBound.Discharge.cubeBesovNegativeVectorDepthSeminorm_const
{d : ℕ}
(Q : HCPolySupport.TriadicCube d)
(s : ℝ)
(c : HCPolySupport.Vec d)
(j : ℕ)
:
HCPolySupport.cubeBesovNegativeVectorDepthSeminorm Q s (fun (x : HCPolySupport.Vec d) => c) j = Real.rpow 3 (-s * ↑j) * HCPolySupport.Book.Ch02.vecNorm c
The geometric constant #
noncomputable def
Algsuperdiff.Section24.Sensitivity.Provider.DhBound.Discharge.constantFieldBesovConst
(s : ℝ)
:
The geometric constant of the constant-field negative Besov bound.
Equations
Instances For
The finite-depth bound #
theorem
Algsuperdiff.Section24.Sensitivity.Provider.DhBound.Discharge.cubeBesovNegativeVectorPartialSeminormTwo_const_le
{d : ℕ}
(Q : HCPolySupport.TriadicCube d)
{s : ℝ}
(hs : 0 < s)
(N : ℕ)
(c : HCPolySupport.Vec d)
:
(HCPolySupport.cubeBesovNegativeVectorPartialSeminormTwo Q s N fun (x : HCPolySupport.Vec d) => c) ≤ constantFieldBesovConst s * HCPolySupport.Book.Ch02.vecNorm c