No Dark Matter or Energy needed

Abstract Standard cosmology attributes roughly 95% of the content of the universe to a dark sector—dark matter and dark energy—in order to explain galactic rotation curves, gravitational lensing in cluster collisions, structure formation, and the accelerated expansion. Yet decades of direct-detection experiments have found no dark matter particles, and recent data suggest that dark energy may evolve over time. This paper presents a conceptual framework, as yet without formal equations, that proposes replacing both components with geometric and mechanical properties of spacetime in a braneworld scenario. We propose that primordial defects—"wrinkles" and "knots" in spacetime—act as gravitational cradles for galaxy formation and carry a finite relaxation memory, which would account for dark matter phenomenology in galaxies and clusters, including the offset between gas and gravity in the Bullet Cluster. In the early universe, these "frozen wrinkles" would dilute like non-relativistic matter and feel no radiation pressure, thereby preserving the acoustic peaks of the cosmic microwave background. At the same time, an exogenous gravitational tension from the bulk would stretch the brane: through stress concentration around stiffer knots, voids would expand preferentially, mimicking a cosmological constant. We propose falsifiable tests with DESI, Euclid, JWST, and Cosmicflows-4, including the time decay of lensing-gas offsets in cluster mergers and a search for a spacetime-memory wake trailing moving galaxies.