{
  "annotation_id": "3b50d33c-1ba3-4c83-a192-d984025ca6d7",
  "date_created": "2026-03-02T18:00:49.856000Z",
  "date_modified": "2026-03-02T18:00:49.856000Z",
  "file_hash": "daa9cc3d3a0d4a7ae778a84b4473d34cfc0e6f77bfc4d210dad145436e544213",
  "private": false,
  "record": {
    "abstract": "One can make the very simple hypothesis that the Universe is the inside of an\nhypersphere in 4 dimensions, where our 3-dimensional world consists of\nhypersurfaces at different radii. Based on this assumption it is possible to\nshow that Universe expansion at a rate corresponding to flat comes as a direct\ngeometrical consequence without intervening critical density; any mass density\nis responsible for opening the Universe and introduces a cosmological constant.\nAnother consequence is the appearance of inertia swirls of expanding matter,\nwhich can explain observed velocities around galaxies, again without the\nintervention of dark matter. When restricted to more everyday situations the\nmodel degenerates in what has been called 4-dimensional optics; in the paper\nthis is shown to be equivalent to general relativity in all static isotropic\nmetric situations. In the conclusion some considerations bring the discussion\nto the realm of 4D wave optics.",
    "arxiv_id": "physics/0402075",
    "authors": [
      "Jose B. Almeida"
    ],
    "categories": [
      "physics.gen-ph"
    ],
    "title": "An hypersphere model of the Universe - The dismissal of dark matter",
    "url": "https://arxiv.org/abs/physics/0402075"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "a4423855-e674-45e2-8d64-d2fda5c23720",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}