Paper 175E Collective Source Reaction and the Stability of an Acoustic Correlation Scale

Reciprocal contact sources on the occupied face-centered-cubic structure can destabilize a finiteband of inventory wavelengths while leaving the long-wavelength limit stable. This paper derives thatresponse from the conservative population Hamiltonian and calibrates its source stiffness, inertia andcoupling magnitude through uniform frequencies and contact currents measured at two inventorybackgrounds. The unstable band, complete coupled frequencies and acoustic stiffness then becomelinked predictions, constrained by an exact scale–stability-margin relation. Nonlinear and numericaltests establish the limits of that mechanism: a stationary planar stripe has an oblique instability,and two full 643 coordinate-box preparations retain a negative correlation dip followed by a positivemaximum in three fixed temporal averages, with outer radii 25.70a–26.25a while angular departuresincrease. First-window step refinement changes the normalized raw radial curve by at most .00130on the declared grid, despite a relative endpoint-field difference of .844. These results support acalibrated native correlation mechanism; they do not establish trajectory convergence, isotropy ora cosmological ruler. Physical identification still requires independently fixed source populations,matter readout, length and clock units, cosmological evolution and observation maps. The completereal reference program is included.