We develop an effective phenomenological framework for weak-field gravitational dynamics motivated by analogy with classical electromagnetism in material media. By modeling the gravitational field with a constitutive response function g, analogous to permittivity or permeability in electromagnetism, we construct a Maxwell-like field equation applicable in the non-relativistic regime. Under observational constraints from solar-system dynamics and galactic rotation curves, the low-acceleration limit reproduces the phenomenology associated with Modified Newtonian Dynamics (MOND), including the baryonic Tully--Fisher relation, while the high-acceleration limit reduces to Newtonian gravity. The framework incorporates known gravitomagnetic effects and includes a uniform effective phantom density associated with the cosmological constant, representing the gravitational contribution of vacuum energy in the Newtonian limit. We further outline how both the nonlinear gravitational response g and the background phantom density may arise from a common scalar-field effective action describing the gravitational vacuum. The resulting formulation provides a phenomenological framework relevant to galactic dynamics and large-scale cosmological background effects, including possible connections between low-acceleration gravitational scales and the observed late-time expansion of the Universe.
Ralph C DeMartino (Sun,) studied this question.