THE DISSIPATIONLESS BULK AND COSMOLOGICAL SIGNATURES (XXXV v6) Bulk Shear Wave Mechanics, Transverse Orthogonality, the No-Drag Theorem, and Inter-Brane Resonances

In the FCD-RBv6 pregeometric framework, wave propagation, celestial mechanics, and cosmological signatures are derived from the elastodynamics of the incompressible AdS5 bulk regularized at the Compton floor R0 ≈ 0.6308 fm. Five core principles are formalized: (1) Bulk Shear Wave Mechanics: transverse S-modes governed by the linear constitutive identity μ_bulk = ρ_bulk c² strictly enforce zero group velocity dispersion (d²ω/dk² = 0), ensuring that electromagnetic and gravitational waves travel without dissipation across cosmological baselines; (2) Transverse Orthogonality (E ⟂ B ⟂ k): electric fields represent planar direct shear strains, magnetic fields represent coupled orthogonal torsional vorticity, and antipodal helicity interference (h_A1 = +1, h_A2 = -1) stabilizes non-radiative phase rails; (3) The No-Drag Theorem (F_drag = 0): celestial bodies anchored at R0 experience zero secular drag because gravitational interactions are mediated by statistical phase-space depletion at zero entropy (S = 0) with strict adiabatic invariance (dS = 0), supported by quantum interface theorems (Maj & Nair 2024; Asorey & Muñoz-Castañeda 2008); (4) Multi-Messenger Coincidence: the exact equality of gravitational and light speeds (|v_gw - c|/c < 10^-17) emerges naturally from the shared elastic saturation speed c of the bulk; and (5) Inter-Brane Resonances: standing bulk shear harmonics project testable metric echoes in high-order CMB multipoles (ℓ > 1500). All couplings preserve topological braid invariants and exclude mechanical aether drag.