The Causal Response Framework

This monograph-length, technical investigation examines the sufficiency of instantaneous gravitational inference in galaxies using a regime-based, falsification-driven program. Through matched-pair and population-level analyses, the work identifies a persistent identifiability failure—referred to here as the Twin Galaxy Paradox—in which closely baryon-matched systems exhibit systematically distinct outer kinematics under identical present-day conditions. Across spirals, dwarfs, and clusters, this failure survives multiple adversarial tests and necessitates a causal, retarded response when interpreted within standard instantaneous frameworks, without introducing new particles, force laws, or phenomenological tuning. The analysis is explicitly non-cosmological and defers early-universe implications. A cumulative adjudication is presented, emphasizing termination, boundary-setting, and internal consistency rather than model fitting or statistical preference. A concluding coda reports an empirical temporal ordering of the deviation without assigning cosmological interpretation, motivating—but not executing—a subsequent treatment of long-timescale dynamics.