Expand two real fields in a finite orthonormal spatial band. With canonical
coefficients Qj,Pj, write Ij=(Qj2+Pj2)/2, and choose phases
so that θ˙j=∂H/∂Ij. Let
ej=νjIj, where the bare rates νj>0. Define
Set F=1 when the set is empty. This is an explicitly nonlocal spectral
interaction of the same field. Its modal frame and finite band are additional
premises. The complete variation gives
Both H0 and total action ∑Ij are conserved. Every uniform
preparation ej=e0>0 is an exact invariant family, with
H=De0 and unchanged phase rates νj. At H0=Dε,
j∑(ej−ε)2≤κ(1−∣η∣)2ε(H−H0).
Small energy deviations therefore stay small for all time. Below the bound
that keeps all energies positive, the finite-dimensional smooth flow is
global. There is reciprocal energy exchange away from the uniform family:
for ν=(1,2,3), resonance (1,−2,1), and
e=(11/10,3/5,13/10), choosing the resonant phase π/2 and
ε=κ=1,η=1/2 gives
e˙=(13/200,−13/50,39/200).
This sustains equal energy but does not attract arbitrary initial conditions
or select e0=ε. The mismatch energy is conserved. The action
also requires a physically justified modal frame within degenerate shells.
The same rule works at all six depths; at D=1 the mismatch vanishes.
A positive arithmetic comparison spectrum νk=ωd(k+1) permits
the rule, but is not the actual disturbance spectrum of the entropy core.
The latter includes neutral modes that cannot carry positive oscillator
energy through ej=νjIj.
Coherence Does Not Require a Single Degenerate Shell
For real spatial modes uj, a paired field
z=∑ajuje−iνjt has stationary squared magnitude precisely
when every nonzero beat coefficient vanishes pointwise:
νj−νk=Δ∑ajak∗ujuk=0(Δ=0).
Generic overlapping scalar modes beat. Bounded beats, orthogonal real
component planes and nonlinear phase locking are distinct possible patterns;
stationary density is not a universal persistence requirement. Integral
orthogonality alone does not remove local beats.
An explicit projected quartic example uses normalized weighted-ball modes
u0=1, u1=d+3x1, with
Cd=∫u14=3(d+3)/(d+5). For