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Shadow Theory

Section 12 4 October 2026

Rotor wave and velocity-weighted error

Reading position 14 of 37

12 Rotor wave and velocity-weighted error

In one sector write z=(X−o)/h−i/2−diz=(X-o)/h-i/2-d_i, ωi=gi/α\omega_i=\sqrt{g_i/\alpha}, and bi=cos⁡(ωit)b_i=\cos(\omega_i t). Let aηta_{\eta_t} be the unnormalized quintic taper: one on ∣z∣≤1/2−2ηt|z|\le1/2-2\eta_t, zero on ∣z∣≥1/2−ηt|z|\ge1/2-\eta_t, and a S5S_5 transition between. The harmonic compact comparison carries amplitude aηt(z/bi)/2bia_{\eta_t}(z/b_i)/\sqrt{2b_i} and phase −αKωitan⁡(ωit)z2/2-\alpha K\omega_i\tan(\omega_it)z^2/2 in each cell.

The physical initial wave is 1/21/\sqrt2, so its initial error is not zero. Exact integrals give

d02=643ηt231,A12=207ηt,A22=2407ηt3,A32=1440ηt5. d_0^2=\frac{643\eta_t}{231},\quad A_1^2=\frac{20}{7\eta_t},\quad A_2^2=\frac{240}{7\eta_t^3},\quad A_3^2=\frac{1440}{\eta_t^5}.

The comparison lies in the quadratic potential core whenever it is used. Its residual norm is A2/(2αKbi2)A_2/(2\alpha Kb_i^2).

Lemma 12.1 (Finite rotor comparison)

Through capture time tb=1.28t_b=1.28, let rir_i be the exact rigid-sector wave. Then

∥ri−Φi∥≤d0+ϵR=:d,ϵR=2A2.999K, \norm{r_i-\Phi_i}\le d_0+\epsilon_R=:d, \qquad \epsilon_R=\frac{2A_2}{.999K},
∥pX(ri−Φi)∥mh≤A1.999K+.501d0+4.02A3K2+1.002ϵR=:q. \frac{\norm{p_X(r_i-\Phi_i)}}{mh} \le \frac{A_1}{.999K}+.501d_0+\frac{4.02A_3}{K^2} +1.002\epsilon_R=:q.

For the selected row, d<D=.007233d<D=.007233 and q<Q=.003983q<Q=.003983.

Proof

The residual norm integral uses ωit<1.3\omega_it<1.3 and tan⁡1.3<4\tan1.3<4. The static nonnegative rotor Hamiltonian propagates its own square-root norm. Multiplying that estimate by 2/(αK)\sqrt{2/(\alpha K)} gives the initial derivative contribution A1/(αK)+ωid0/2A_1/(\alpha K)+\omega_i d_0/2. Differentiating the residual introduces A3/(2α2K2bi3)A_3/(2\alpha^2K^2b_i^3) and its harmonic phase derivative; the potential part adds the same ωi/2\omega_i/2 residual bound. Integrate with ∫01.3sec⁡3θ dθ<8\int_0^{1.3}\sec^3\theta\,d\theta<8, ωi<1.002\omega_i<1.002, and 4/(α2ωi)<4.024/(\alpha^2\omega_i)<4.02. Weak H3H^3 taper derivatives suffice; no fourth derivative of the sharp taper is invoked. The outward rational square-root calculation in Appendix A proves the final decimals.

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At ta=1.22t_a=1.22, each Φi\Phi_i is supported in its own outcome region even with ∣di∣≤.01|d_i|\le.01. The wrong-side wave probability is at most D2D^2. For the isolated spinor rotor, the guidance map commutes with X↦X+hX\mapsto X+h. The initial preimage of the classifier is therefore periodic, including its circle circulation. Lemma 11.1 and the wrong-side estimate yield the actual isolated-label error

∣P(ℓ(Xtaiso)=1)−p∣≤12N+D2. |P(\ell(X^{\rm iso}_{t_a})=1)-p|\le\frac1{2N}+D^2.