Skip to content
Shadow Theory

Appendix CSPC-2 · Version 2

Record witnesses and quantitative limitations

Reading position 33 of 37

C.1 Finite jet determination without an order bound

Let WW be a finite-dimensional real observable carrier and suppose each scalar expectation sωs(A)s\mapsto\omega_s(A) is real analytic on a connected open domain. Let KjK_j be the subspace of witnesses whose derivatives through order jj vanish at s0s_0. Analytic uniqueness gives

j0Kj={A:ωs(A)=0 on the domain}. \bigcap_{j\ge0}K_j=\{A:\omega_s(A)=0\text{ on the domain}\}.

There are finitely many strict dimension drops, so there is a finite order beyond which the subspaces stabilize to that intersection. The order itself is not bounded by dimW\dim W: arbitrary stretches of equal successive kernels can precede a later drop.

For a concrete example, take ρs=I/2+smZ/4\rho_s=I/2+s^mZ/4 near s=0s=0 and A=ZA=Z. Then tr(ρsZ)=sm/2\tr(\rho_sZ)=s^m/2. The first nonzero derivative occurs at the arbitrarily chosen order mm, while the ambient Hermitian carrier has dimension four. This rules out a dimension-only upper bound on the detecting jet order and a stopping criterion based only on one consecutive equality. The valid eventual finite-determination result is retained; the stronger algorithmic claim requires an extra degree or differential-closure hypothesis.

All derivatives in this statement are taken in a specified coordinate chart. Higher ordinary derivatives of a scalar function are not automatically invariant tensors under arbitrary nonlinear coordinate changes. A coordinate-free formulation must use a jet bundle or an explicitly chosen connection. The finite linear solvability problem itself is unaffected by this distinction.

C.2 Positive witnesses and physical implementation

With evaluation map E:WRm\mathcal E:W\to\R^m, the set of witnesses for target yy is either empty or an affine coset A0+kerEA_0+\ker\mathcal E. Requiring positivity intersects this affine set with the positive semidefinite cone. The result is closed and convex; it is not generally a face of that cone.

If one calibration state obeys ρλI\rho_*\ge\lambda_*I with λ>0\lambda_*>0 and every positive witness has expectation gg_* in that state, then

λtrAtr(ρA)=g. \lambda_*\tr A\le\tr(\rho_*A)=g_*.

Thus AtrAg/λ\norm A_\infty\le\tr A\le g_*/\lambda_*, and the positive-witness set is compact in finite dimension. A nonempty compact convex set has extreme points. A witness AA is extreme exactly when no nonzero HkerEH\in\ker\mathcal E satisfies A±H0A\pm H\ge0. These statements describe mathematical feasibility; an accessible implementation of a chosen witness requires an admitted instrument.

C.3 Approximate capacity of a finite record

Suppose MM equiprobable historical labels are encoded into states ρ1,,ρM\rho_1,\ldots,\rho_M on a Hilbert space of dimension DD, and a POVM {Ei}\{E_i\} decodes them with average success at least 1ϵ1-\epsilon. Since ρiI\rho_i\le I,

1ϵ1Mitr(Eiρi)1MitrEi=DM. 1-\epsilon\le\frac1M\sum_i\tr(E_i\rho_i) \le\frac1M\sum_i\tr E_i=\frac DM.

Hence

D(1ϵ)M. D\ge(1-\epsilon)M.

For M=2nM=2^n independent binary histories, perfect retention gives D2nD\ge2^n and approximate decoding gives the displayed weakened bound. This is a resource requirement for distinguishing historical alternatives, not a lower bound on consciousness. It also does not forbid repeatedly using one register when old independent histories are not required to remain available.

C.4 An exact probability countermodel and its repair condition

The following example delimits a tempting use of closure. Let DBρD_B\rho be diagonalization in a fixed record basis and

c(ρ)=ρDBρHS2,ρ~=(1c)DBρ+cI/d. c(\rho)=\norm{\rho-D_B\rho}_{HS}^2, \qquad \widetilde\rho=(1-c)D_B\rho+cI/d.

For density matrices 0c10\le c\le1. The assignment p(Eρ)=tr(Eρ~)p(E\mid\rho)=\tr(E\widetilde\rho) is positive, normalized, additive on orthogonal effects, continuous, and equivariant under record-basis-preserving unitaries. It agrees with ordinary diagonal calibration and converges under the constant closure channel Tρ=I/dT\rho=I/d. Yet for

ρ=(3/41/41/41/4) \rho=\begin{pmatrix}3/4&1/4\\1/4&1/4\end{pmatrix}

it gives p0=23/32p_0=23/32, not 3/43/4. Those stability and fixed-basis conditions alone therefore do not force Born weighting.

An additional affinity premise can remove this freedom for the fixed record measurement. Suppose pi(ρ)p_i(\rho) is affine on all density operators, lies in [0,1][0,1], and obeys pi(jj)=δijp_i(\ket j\bra j)=\delta_{ij}. Finite-dimensional duality gives an effect FiF_i with pi(ρ)=tr(Fiρ)p_i(\rho)=\tr(F_i\rho). Its diagonal is fixed by calibration. Positivity implies (Fi)jk2(Fi)jj(Fi)kk|(F_i)_{jk}|^2\le(F_i)_{jj}(F_i)_{kk}, so every off-diagonal entry vanishes. Hence Fi=iiF_i=\ket i\bra i and pi(ρ)=ρiip_i(\rho)=\rho_{ii}.

This is an exact conditional derivation from affinity and full state-domain positivity, not a derivation of those premises from contraction. The physical measurement completions retain their own probability-bearing preparation assumptions. The example is included to state the correct theorem boundary, not to deny the existence of well-defined quantum decision or measurement models.

C.5 Physical archive corruption and wave error

For a flat archive boundary Σ\Sigma in full configuration space, the normal probability current of the internal-vector wave is (/m)ImΨ,nΨ(\hbar/m)\operatorname{Im}\langle\Psi,\partial_n\Psi\rangle. Suppose the nominal held wave has zero normal current pointwise on that surface, and the actual wave is Ψ=Ψ0+ξ\Psi=\Psi_0+\xi. Surface norms integrate all remaining spatial variables, including the clock. The cross terms and Cauchy–Schwarz yield

Σjn(Ψ)m(Ψ0L2(Σ)nξL2(Σ)+ξL2(Σ)nΨ0L2(Σ)+ξL2(Σ)nξL2(Σ)). \int_\Sigma |j_n(\Psi)|\le\frac{\hbar}{m} \left(\norm{\Psi_0}_{L^2(\Sigma)}\norm{\partial_n\xi}_{L^2(\Sigma)} +\norm\xi_{L^2(\Sigma)}\norm{\partial_n\Psi_0}_{L^2(\Sigma)} +\norm\xi_{L^2(\Sigma)}\norm{\partial_n\xi}_{L^2(\Sigma)}\right).

Here the Sobolev norm differentiates the system/archive coordinates, with clock and other spectator coordinates treated as L2L^2 parameters. The trace inequality is correspondingly Hilbert-valued and integrated over those parameters; it does not differentiate the rapidly oscillating clock phase. Under a specified H2H^2 trace bound CΣC_\Sigma, Ψ0H2B\norm{\Psi_0}_{H^2}\le B, and ξH2ϵ2\norm\xi_{H^2}\le\epsilon_2, integration over an interval II gives

I ⁣ΣjnmICΣ2ϵ2(2B+ϵ2). \int_I\!\int_\Sigma |j_n|\le \frac{\hbar}{m}|I|C_\Sigma^2\epsilon_2(2B+\epsilon_2).

For the deterministic configuration-guidance flow v=j/ρv=j/\rho, the regular-surface crossing formula gives

ENΣ(I)=I ⁣Σjn,P(NΣ(I)1)ENΣ(I), \mathbb E N_\Sigma(I)=\int_I\!\int_\Sigma |j_n|, \qquad P(N_\Sigma(I)\ge1)\le\mathbb E N_\Sigma(I),

under the stated flow regularity and the usual regular crossing hypotheses for the chosen surface. The estimate therefore bounds historical corruption that requires such a crossing. Equivariance alone would not suffice: a stationary equivariant diffusion can cross a boundary while the Schrödinger current is zero. Ordinary L2L^2 endpoint closeness likewise supplies no derivative or surface bound. The archive conclusion uses the specified guidance paths and the stronger physical norm together.