Ramified Arithmetic Coordinates: The Arithmetic Event Horizon and the Neglecton Framework

We introduce Ramified Arithmetic Coordinates (RAC), a structural framework isolating the central obstruction in the Generalized Riemann Hypothesis (GRH) as a ramification phenomenon at the central point s = 1/2. Building on unconditional results established in the companion work—Selmer vanishing, Iwasawa flatness (= 0), and p-adic non-vanishing—we identify the remaining difficulty as a failure of the Fontaine comparison for non-de Rham representations. The central point is interpreted as a coordinate singularity of an arithmetic covering, where the classical comparison functor degenerates: D₃ₑ (V (1/2) ) = 0, while a replacement structure—the modified trace in a non-semisimple categorical setting—remains non-vanishing. This leads to a new geometric and categorical model of the obstruction. We construct a finite-level modified comparison functor Comp^modN, and prove it is exact, faithful, monoidal, and Q-valued. We introduce the Kummer mass as a ramification invariant and establish its stability across GL (1), GL (2), and low-rank functorial lifts. An Arithmetic Uncertainty Principle is derived from the product formula and Mahler expansions, quantifying the height barrier at the central point. The framework unifies multiple phenomena—duality degeneration, categorical trace detection, and arithmetic ramification—into a single structure. The central point emerges as an arithmetic event horizon, where coordinate systems collapse and must be replaced. We distinguish rigorously between: Unconditional results (finite-level comparison, Selmer vanishing, mass invariants), Structural identifications (ramification geometry, degeneration patterns), Conjectural extensions (infinite-level comparison and GRH equivalence). Physical parallels (duality, horizon structure, statistical mechanics) are presented as structural consequences, not inputs. The framework provides a precise reformulation of GRH as a comparison problem across a ramified arithmetic covering, isolating the final obstruction.