{"paper":{"title":"A Cosmological Tale of Two Varying Constants","license":"","headline":"","cross_cats":["gr-qc"],"primary_cat":"astro-ph","authors_text":"H.B. Sandvik, J.D. Barrow, J. Magueijo","submitted_at":"2002-04-21T14:26:12Z","abstract_excerpt":"We formulate a simple extension of general relativity which incorporates space-time variations in the Newtonian gravitation 'constant', $G$, and the fine structure 'constant', $\\alpha $, which generalises Brans-Dicke theory and our theory of varying $\\alpha .$ We determine the behaviour of Friedmann universes in this theory. In the radiation and dust-dominated eras $\\alpha G$ approaches a constant value and the rate of variation of $\\alpha $ is equal to the magnitude of the rate of variation in $G$. The expansion dynamics of the universe are dominated by the variation of $G$ but the variation "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0204357","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}