Cosmic Wormhole Dynamics: A Geometric Model for Cosmic Expansion

We present the Cosmic Wormhole Dynamics (CWD) framework, in which the universe is described as a four-dimensional hypersurface embedded in a five-dimensional wormhole spacetime. In this picture, the observed late-time acceleration is driven by the dynamical evolution of the wormhole throat radius, removing the need for a cosmological constant or fine-tuned dark energy. Dimensional reduction of the five-dimensional Einstein equations in the presence of a scalar field and exotic matter produces effective four-dimensional Friedmann equations together with a Yukawa-like modification to the Newtonian potential. For extended baryonic distributions this leads to a morphology-dependent coupling