DCRP61 / X72R44: Stress Projection and the Aligned Neutral Floquet Mode

Building on the frontier question DCRP60 selected — whether non-affine vorticity stretching N implies an X72 visibility defect or turnover T — this round applies the projection and realizability tools of X72 Round38, 42, and 43 to test it. It derives the proper evolution equation for the actual vorticity stress W, splitting the stress change into an amplitude-stretching part λ and a directional-tilt part τ, and proves that pure eigen-aligned stretching (τ=0) only rescales the stress cone without rotating or deforming it — thereby locating an equality direction invisible to X72's projection attack: a spatially uniform eigen-aligned stretch that, at the proper neutral Floquet averaging rate (2−3γ)/2, can sustain a periodic isotropic covariant without triggering turnover. The general implication DCRP60 had envisioned, 'N⇒X∨T', is thereby refuted, leaving only modulation, tilt, or the transport–projection commutator as mechanisms that could make stretching visible to X72. STOP-D61 hands to DCRP62/X72-R45 the still-open question of whether this invisible eigen-aligned mode can simultaneously sustain a perfect pressure response.