This work presents an effective viscoelastic framework for galactic dynamics, in which the observed radial acceleration relation (RAR) emerges as a quasi-steady outcome of a delayed gravitational response. The model introduces a cosmologically motivated relaxation timescale (τ ∝ H⁻¹), leading to an emergent acceleration scale a0 ~ cH. Within this framework, galaxy rotation curves, the RAR, and the baryonic Tully–Fisher relation are reproduced without invoking particle dark matter or modifying general relativity at a fundamental level. In addition, a dimensionless memory parameter (τ / tdyn) provides a natural interpretation of the observed scatter in the RAR. This version corresponds to a revised and clarified presentation of the dynamical framework.
Chang-sik Kim (Sun,) studied this question.