AdjointResponse #
Ported from scottnarmstrong/Superdiffusion at 7f20476385d4af418f110303085ad0740c9eba46. Module imports, support namespace and local option directives adapted for Lean Pool.
The adjoint response identity #
Source: ABK26. The proof of l.Dh.bound needs the energy of the adjoint
half w* = ½ v(·, □₀, p, -q; aᵗ) expressed through the primal response
functional. In the coarse-matrix coordinates the two response functionals
differ only by the sign of the κ term, so
J(U, aᵗ, p, -q) = J(U, a, p, q) + 2 p · q .
Both sides are unconditional: the canonical coarse-matrix formula
responseJ_eq_coarseMatrices_formula_canonical and the adjoint formula
ResponseMagicIdentitiesTheory.adjoint_quadratic hold at every Chapter 2 domain
and coefficient.
The identity is what converts the adjoint energy (P · 𝐀 P)/2 - 2J of the
source proof into the frozen budget shape √J + √|p · q|.
Sign bookkeeping for the quadratic form #
The adjoint response identity #
Adjoint response identity. Flipping the coefficient to its transpose and
the second loading to its negative shifts the response functional by 2 p · q.