Simple Gravity: A Scalar Refractive Framework for Gravitational Phenomena

This work presents Simple Gravity, a scalar formulation of gravitational phenomena based on an exponential modification of propagation governed by a gravitational potential Φ, with an effective refractive index n(Φ) = e^{-2Φ/c^2}. The framework reproduces the leading-order predictions of General Relativity for light deflection and Shapiro time delay, while introducing well-defined higher-order deviations. These deviations remain consistent with current observational constraints and provide clear testable predictions in high-precision regimes. The theory predicts a distinct strong-field structure characterized by continuous suppression of signal propagation without the formation of a finite-radius event horizon. This leads to an alternative interpretation of compact objects and black hole observations. Observable consequences include second-order corrections to light deflection, modifications to the Shapiro time delay, and strong-field effects potentially distinguishable in gravitational lensing and Event Horizon Telescope observations. The results establish Simple Gravity as a consistent and testable non-geometric framework for gravitational physics.