As the first proposer of this theory and an independent researcher, I would like to share a new theoretical framework that addresses the systematic discrepancy between inferred and observed gravitational acceleration in galaxies.
While this phenomenon is typically interpreted as evidence for dark matter , my research proposes an alternative: an effective viscoelastic spacetime framework. In this model, spacetime is not a perfectly elastic medium, but instead behaves as a geometric structure capable of storing and relaxing curvature strain over a finite timescale.
Key features of the model: * Cosmological Connection: The model introduces a relaxation timescale proportional to the Hubble time, $\tau\propto H^{-1}$, leading to a characteristic acceleration scale $a_{0}\sim c/\tau$. * Emergent Dynamics: This delayed gravitational response naturally reproduces key empirical relations in disk galaxies—including the radial acceleration relation (RAR), flat rotation curves, and the baryonic Tully-Fisher relation. * No Dark Matter Required: The quasi-steady solution explains the observed mean RAR without invoking particle dark matter or modifying general relativity at a fundamental level.
The full manuscript, "Galaxy Rotation Curves and the Radial Acceleration Relation in an Effective Viscoelastic Spacetime Framework", is currently under peer review. However, to foster early discussion and gather constructive feedback from the community, the preprint is openly accessible.
I welcome any thoughts, critiques, or discussions regarding the macroscopic consequences of a cosmologically driven, non-equilibrium gravitational response.
Read the full preprint here: > DOIÂ 10.5281/zenodo.19790016
Chang-Sik Kim is an independent researcher in theoretical astrophysics based in South Korea. His work centers on the Effective Viscoelastic Model (EVM), a theoretical framework proposing that spacetime exhibits memory-like, delayed gravitational responses to baryonic matter distributions at galactic scales. Rather than invoking undetected dark matter particles, EVM explores the possibility that the excess gravitational effects observed in galactic rotation curves and the Radial Acceleration Relation arise from the temporal, non-instantaneous nature of the gravitational field itself. He is a member of the Korean Physical Society and maintains a publication record on Zenodo (ORCID: 0009-0000-0601-5113).