with all fixed-order derivatives bounded independently of its translated center. The exact energy and norm estimates imply, for one constant independent of ,
Any bounded second-order expansion agreeing with the fixed-direction
variations would instead have a nonnegative quadratic term and a remainder
, a contradiction. The argument also excludes an agreeing
extension in each fixed finite integer derivative norm with the same
weight. It does not assert that an entire weighted Sobolev ball is
an injective pointwise sphere chart, or address every possible nonlinear
phase-space chart. Stronger norms imposing uniform relative smallness are
outside the argument. No dynamical instability or failure of electron
persistence follows. The principal weighted-energy-taylor.md and its
independent 64-check review supply the exact formulation.
Low Frequencies In The Complete Coupled System
The constant-inertia coupled system has disturbance frequencies arbitrarily close to zero at every maintained depth, including ten. This strengthens the unused-frame comparison: it retains occupation, phase, support, frame and flow. It does not classify the entire spectrum or prove nonlinear stability.
For the normalized common-phase coordinate , an escaping packet with fixed unit-norm smooth compact has and . The other coordinates initially vanish. Static zero states have occupation and flow zero and , where ; their phase part is therefore proportional to . Subtracting that exact phase zero state makes the packets orthogonal to the entire kernel without changing their limiting residual. Thus the static operator has zero in its essential spectrum even after its kernel is removed.
That fact alone would not prove positive disturbance frequencies tending to zero. For example, with a nonzero two-coordinate skew gyro coupling has an exact zero branch and a positive branch bounded away from zero. The actual full pencil must be tested.
At spatial infinity the normalized coefficients have constant limits. The support/flow derivative coupling and logarithmic density gradient vanish, while the phase/support gyro coefficient remains . The support square retains
The other terms retain the carrier/frame derivative square, positive occupation Hessian, phase-edge Hessian, frame/flow gradients and the positive phase-flow completion. In the full Hermitian pencil , at every nonzero the static kernel is the one support direction . The gyro compression on this kernel is zero; eliminating its positive complement leaves a strictly negative coefficient of . Hence the pencil has one negative eigenvalue for sufficiently small positive at fixed nonzero .
At , write for the phase Hessian and . The phase/support gyro pair has one positive and one negative eigenvalue near zero frequency. The remaining soft coordinates add negative directions. For positive phase edges, , giving across depths . For zero phase edges replace by . Continuity at any sufficiently small fixed positive frequency, followed by sufficiently small nonzero , therefore forces at least positive-frequency crossings counted with multiplicity. Their frequencies can approach zero. This argument retains both edge cases and does not infer dynamics from the static Rayleigh quotient.
For each fixed root, multiply its constant-limit plane wave by a widening
cutoff translated farther into the tail. Actual coefficients and the
necessary derivatives converge on its support, giving a weakly vanishing
approximate eigenvector of the closed energy-space
generator. A closed-range estimate with finite-dimensional kernel would
contradict these packets. Thus these imaginary frequencies belong to its
Fredholm essential spectrum. They are not claimed to be localized
eigenmodes. The finite-carrier proof is in coupled-zero-threshold/report.md
and the independent 43-check coupled-threshold-review/report.md.
Flat-Core Approximate Standing Disturbances
For each fixed integer , the changed flat-core density , , gives the exact scalar