We present the Matter-Originated Spacetime Gradient Model (MOSGM), a covariant scalar-tensor modified gravity framework derived from a first-principles action. The model produces modified Einstein equations, a baryonic matter sourced scalar field equation, and a proof of total energy-momentum conservation. MOSGM adopts an exponential interpolation function that recovers both Newtonian and deep-MOND limits. A first-principles derivation of the External Field Effect (EFE) yields a positive-definite anisotropic diffusion tensor and a parameter-free environmental suppression prediction. A pilot observational consistency test using a stacked sample of 15 galaxy clusters shows weak statistical preference (Δ ln L = 1.63) relative to a standard phenomenological suppression law. The work is intended as a falsifiable framework with clear predictions for high-external-field environments rather than a complete alternative to ΛCDM. Version v4 includes statistical clarification, formatting corrections, and improved observational presentation. All analysis uses publicly available datasets (MCXC, NED, SIMBAD).
TARUN KUMAR SAXENA (Thu,) studied this question.