System-Dependent Gravitation as Selective Stabilization of Motion

This paper proposes a structural reformulation of gravitation as a system-dependent selection mechanism acting on admissible continuations of motion. Instead of treating gravity as a force or as locally generated spacetime curvature, gravitational behavior is interpreted as the progressive elimination of non-admissible trajectory continuations imposed by the global stability requirements of a physical system. Motion is modeled as inertial continuation constrained by system-specific admissibility sets defined on the tangent space. The realized trajectory emerges through minimal deviation from inertial motion under structural compatibility constraints, formalized as a projected dynamical process or differential inclusion. No additional gravitational fields, dark matter components, or scale-dependent laws are introduced. Within a single unified mechanism, the framework reproduces qualitatively distinct gravitational regimes: radial infall near planetary bodies, stable orbital families in stellar systems, and coherent galactic rotation patterns without invoking unseen mass. Differences in gravitational behavior arise from differences in system structure rather than differences in fundamental physical law. The approach provides a coherent causal interpretation of gravitational plurality across scales and aligns naturally with hierarchical and pre-realizational selection principles, offering a structural alternative to both force-based and curvature-based descriptions of gravitation.