Topological Decoherence and Relational Coarsening in Chern-Simons Boundary Cosmology: Derivation, Obstructions, and Open Problems

We derive the post-degeneracy dynamics of a (2+1)D SL(2,C) Chern-Simons boundary theory emerging from degenerate disformal scalar-tensor gravity. The complex level k_eff = s + it generates an exponential topological decoherence filter that selects minimal-volume hyperbolic geometries. Honest derivation of domain coarsening yields exponent n = 1/3 (Ostwald ripening under volume conservation); the observational exponent 2/3 requires a network sparsity hypothesis (R ~ L^2) formulated as an open conjecture. A Spin-TQFT path toward Majorana neutrino mass from surgery holonomy is sketched, with the SL(2,C) symmetry obstruction explicitly identified. Five open problems are enumerated. Builds on the No-Go Theorem (DOI: 10.5281/zenodo.18866200) and CS Boundary Completion (DOI: 10.5281/zenodo.18894178). Additional notes (Changelog for Version 2) Transition from Hypothesis to Theorem: The cosmic scaling law R(t) ~ t2/3 has been formally derived via the Volumetric Traversal Postulate (Definition 6.4). This derivation establishes that in a post-degeneracy boundary theory, relational distance is a measure of accumulated Chern-Simons action, which scales as L^2 due to the volumetric nature of the functional. Friedmann Consistency Proof: Added Proposition 6.6, providing a formal proof that the model recovers the p=0 (pressureless dust) Friedmann evolution. The derivation demonstrates that mass conservation (derived from volume conservation in the topological network) leads to the correct energy density dilution of ρ ~ R⁻³. Dimensional Prediction: Introduced a generalized scaling law R(t) ~ t(d-1)/3 for boundary theories of spatial dimension d. The d=3 case, selected by the Achúcarro-Townsend-Witten correspondence, is shown to uniquely predict the observed matter-dominated expansion exponent. Research Programme Refinement: Following the analytical closure of the expansion scaling problem, the primary research focus is now shifted to the Spin-TQFT bridge for the derivation of Majorana mass terms (Open Problem 3).