Candidate collapse-noise correlators from Generalized Trace Dynamics: a Hubble-scale spectral line under structural assumptions

We present a conditional construction of candidate CSL-type collapse-noise correlators inspired by Generalized Trace Dynamics (GTD). The construction is not a parameter-free derivation from the minimal GTD Grassmann algebra. It rests on a chain of explicit structural postulates, listed in Section 1; within that auxiliary structure the spectral form and amplitude follow by computation rather than by phenomenological fitting. The resulting narrow-band spectrum at the Hubble scale lies outside the bands of current CSL bounds, so the framework is not in tension with existing high-frequency data. We compute the two-point function of a candidate collapse-noise operator associated with the GTD aikyon decomposition q_i = q_B + a₀β_i q_F. In the minimal Grassmann algebra, q_F appears only multiplied by Grassmann generators β_i, the reduction of Tr\(q_F^daggerΓ^μq_F\) to ghost-mode operators is obstructed by the nilpotent δβ= β₂ - β₁, and the pure-fermion coefficient β₁β₂ has no ordinary sign, modulus, or inverse. We therefore introduce an auxiliary canonical fermionic Fock-space sector for q_F, equivalently replacing the nilpotent pure-fermion coefficient by an ordinary effective scalar body parameter. This replacement is an independent structural postulate, not a consequence of the original minimal action. Under this auxiliary postulate, together with a scalar bilinear J = Tr\(q_F^dagger q_F\) as bath operator, positive-norm canonical quantization, and an effective sign choice σ= pm1 for the scalarized pure-fermion sector, elementary Wick contraction gives a Wightman line at |ω| = 2ω₀ with amplitude A_J = \(hbar/2m_Rω₀ L_aik²\)^2cdot Ncdot D. The cosmological identification ω₀ sim H₀ places the line at twice the Hubble scale. [truncated]