A Testable Framework for Dark Matter Phenomenology via Geometric Substrate Dilution and Partial Actualisation — Magistral Edition

DOI: 10.5281/zenodo.18591254 This chapter presents a complete, self-contained theoretical framework addressing dark matter phenomenology within Infinite Field Theory (IFT). Dark matter is identified as the Trame Géométrique (Geometric Substrate) — the non-actualised fraction of the informational fabric deployed at cosmological Genesis by the Sentinel Wave. This identification resolves five canonical properties simultaneously: gravitational presence without electromagnetic interaction, the 5:1 dark-to-baryonic mass ratio as a natural actualisation fraction rather than a free parameter, concentration around galaxies, collisionless behaviour, and null direct detection results. The Magistral Edition substantially extends the original formalism with five new contributions: (1) A microphysical derivation of the operational source terms from two independent approaches — information-theoretic statistical mechanics and Wetterich renormalisation group flow with Canet–Delamotte non-equilibrium extension — demonstrating that the activation and dilution terms emerge as universal infrared limits rather than ad hoc ansatze. (2) A complete linear stability cartography mapping the effective mass, sound speed, ghost, and causality conditions across the full parameter grid, confirming that all proposed configurations are free of classical pathologies. (3) Quantitative bounds on the black hole drainage rate derived from cosmological observables (supermassive black hole mass density, integrated accretion history, merger rates), producing optimistic and pessimistic scenarios with explicit predictions for the dilution deviation. (4) A Fisher matrix forecast combining baryon acoustic oscillations, Type Ia supernovae, and weak lensing (Stage IV survey specifications) demonstrating that the primary IFT signature — the dilution deviation δn — is detectable at ≥ 2σ with the joint dataset and ≥ 3σ when Planck CMB priors are included. (5) A pilot implementation protocol specifying a concrete, immediately executable numerical validation programme: a CLASS Boltzmann solver module for linear perturbations and a 100 Mpc/h, 256³ N-body box for non-linear cross-validation. The framework incorporates validation from the Cloud-9 RELHIC discovery (Anand et al. 2025, Hubble Space Telescope — a starless dark matter halo confirming partial actualisation) and the LZ null result (417 live days, December 2025 — consistent with the predicted absence of dark matter particles). The chapter provides the full operational formalism (20 numbered equations), five quantitative tables, explicit falsification channels with numerical thresholds, and a reproducible numerical implementation roadmap. Part of the Grand Dossier Académique du Champ Infini. Keywords : Dark matter phenomenology Cosmological coherence Coherence dilution Partial actualisation Emergent gravitation Non-baryonic mass distributions Large-scale structure Gravitational-only interaction Effective field framework Testable cosmological models Foundational physics Falsifiable dark matter alternatives Information-based cosmology