La Profilée - Gravity as a Persistence Bound: The Global K–R Constraint and the Structural Fragility Zone

The Fine-Tuning of G is standardly framed as a condition for star formation and long-lived structure. This paper derives a structurally prior result: G constrains both K(θ) (global integration) and R(θ) (transformation pressure), and their joint condition IR = R/(F·M·K) ≤ 1 must be satisfied. LP adds a non-obvious prediction: the Structural Fragility Zone — the region of parameter space where IR < 1 is satisfied but IR is near 1. Systems in this zone are persistence-admissible but lack structural reserve. They exhibit specific observable signatures (high perturbation sensitivity, inability to sustain growth, collapse under small shocks) that are absent in the collapse regime and distinct from the flourishing regime. Standard physics identifies a binary: structure forms or it does not. LP identifies three distinct structural regimes.