E0 + E1 · Γ_ε = I − ε K²

Richardson contraction.

The signed selector is squared so the filter is monotone. Minimax step ε* = 2/(μmin+μmax) = 1/99144 equalizes the slowest and fastest complement modes at |λ| = 15/17. Q4.28 is applied to the normalized multipliers, not to unscaled K².

μ⁺_min

11,664

μ_max

186,624

ε*

1/99144

ρ*

0.882353

Engine

cycle 0float r⊥ 0.833364Q4.28 r⊥ 0.833364‖Δx‖ 1.206834e-8

Per-sector multipliers

  • J=0 κ²=32,4000.67320261
  • J=1 κ²=12,5440.87347696
  • J=2 κ²=01.00000000 1
  • J=3 κ²=11,6640.88235294
  • J=4 κ²=19,6000.80230775
  • J=5 κ²=01.00000000 1
  • J=6 κ²=186,624-0.88235294

Stability window 0 < ε < 1/93312. Normalized path uses Ķ = K/432 and α = 32/17 ≈ 1.882353 so Q4.28 never has to store 186624.

Q4.28 monograph table

Published residual trajectory. LSB = 2⁻²⁸ ≈ 3.7253e-9. Hardware floor ≈ 17.6 LSB.

nfloat r⊥Q4.28 r⊥‖Δx‖₂
16.1798e-16.1798e-11.5290e-8
53.3946e-13.3946e-12.7261e-8
101.7022e-11.7022e-13.5095e-8
204.6491e-24.6491e-26.0421e-8
501.0544e-31.0544e-31.3045e-7
1001.9791e-61.9770e-62.5222e-7
1503.7615e-96.5548e-83.1251e-7
2007.1828e-126.5548e-83.1308e-7
2205.8742e-136.5548e-83.1308e-7
2501.3880e-146.5548e-83.1308e-7

Float continues to ~10⁻¹⁴. Q4.28 saturates at 6.554775×10⁻⁸ with no limit cycle because ρ* < 1.