High-contrast homogenization: Provider.Response.ProfileWeakSplit #
Imported from the Apache-2.0 HighContrastHomogenization development at commit
7a13dbcd8d6609264a713373f5c69ceeac870472.
Replacing the random optimizer average by its annealed center #
At every scale, the optimizer state centered at a deterministic vector splits as the state centered at its random parent average plus a fixed field. The scale-average triangle inequality and the exact fixed-field computation give the corresponding normalized seminorm bound.
theorem
HCPolySupport.HighContrast.Response.blockCellAverage_metricRoot_sub_const_diagonalWeakState
{d : ℕ}
{q : Mat d}
(hq : Matrix.PosDef q)
{k t : ℤ}
(hkt : k ≤ t)
{w : Fin d → ℤ}
(hw : w ∈ alignedIndex q k t)
{S : Mat d}
{a : CoeffSpace d}
(p r : Vec d)
(c : BlockVec d)
:
(blockCellAverage (adaptedCellAt q k w) fun (x : Vec d) =>
blockMatVecMul (Book.Ch02.blockDiag S S⁻¹) (diagonalWeakState hq t a p r x - c)) = blockMatVecMul (Book.Ch02.blockDiag S S⁻¹) (blockCellAverage (adaptedCellAt q k w) (diagonalWeakState hq t a p r) - c)
Averaging the metric-root image of a state minus an arbitrary fixed vector commutes with both operations.
theorem
HCPolySupport.HighContrast.Response.profilePrimalWeakRoot_le_randomCentered_add_constant
{d : ℕ}
{q : Mat d}
(hq : Matrix.PosDef q)
(t : ℤ)
{m : Mat d}
(hm : Matrix.PosDef m)
(a : CoeffSpace d)
(p r : Vec d)
(center : BlockVec d)
:
profilePrimalWeakRoot m hq t id p r center a ≤ (ENNReal.ofReal (3 ^ (-(1 / 2 * ↑t))) * adaptedWeakSeminorm q t (1 / 2) fun (x : Vec d) =>
blockMatVecMul (Book.Ch02.blockDiag (matSqrt m) (matSqrt m)⁻¹)
(diagonalWeakState hq t a p r x - blockCellAverage (adaptedCell q t) (diagonalWeakState hq t a p r))) + ENNReal.ofReal constantSeminormCoefficient * ENNReal.ofReal √(metricBlockNormSq m (blockCellAverage (adaptedCell q t) (diagonalWeakState hq t a p r) - center))
The primal normalized weak root splits into its random-centered part and the exact constField correction.
theorem
HCPolySupport.HighContrast.Response.profileAdjointWeakRoot_le_randomCentered_add_constant
{d : ℕ}
{q : Mat d}
(hq : Matrix.PosDef q)
(t : ℤ)
{m : Mat d}
(hm : Matrix.PosDef m)
(a : CoeffSpace d)
(p r : Vec d)
(center : BlockVec d)
:
profileAdjointWeakRoot m hq t id p r center a ≤ (ENNReal.ofReal (3 ^ (-(1 / 2 * ↑t))) * adaptedWeakSeminorm q t (1 / 2) fun (x : Vec d) =>
blockMatVecMul (Book.Ch02.blockDiag (matSqrt m) (matSqrt m)⁻¹)
(diagonalWeakAdjointState hq t a p r x - blockCellAverage (adaptedCell q t) (diagonalWeakAdjointState hq t a p r))) + ENNReal.ofReal constantSeminormCoefficient * ENNReal.ofReal
√(metricBlockNormSq m (blockCellAverage (adaptedCell q t) (diagonalWeakAdjointState hq t a p r) - center))
The adjoint normalized weak root has the analogous split.