Structural Differentiation Gravity (SDG): A Minimal Structural Theory of Gravity

Structural Differentiation Gravity (SDG) proposes a minimal structural formulation of gravity in which gravitational acceleration arises from gradients of structural density. Structural density is defined as a kernel-weighted configuration of surrounding matter, introducing a natural nonlocal structure while preserving the Newtonian limit. We present: • a minimal SDG law • kernel formulation of structural density • an SDG Poisson equation • a relativistic SDG field equation • an action formulation • applications to FRW cosmology • structural perturbations and power spectrum predictions • comparison with ΛCDM cosmology The framework suggests that gravitational phenomena may emerge from structural differentiation of matter distributions rather than purely local mass density. This preprint introduces the minimal formulation of SDG and its cosmological implications. SDG therefore shifts the conceptual basis of gravityfrom local mass sources toward gradients of structural configuration.